diff --git a/lib/rules/multiline-ternary.js b/lib/rules/multiline-ternary.js
index 6668bff4824..98360b9cad4 100644
--- a/lib/rules/multiline-ternary.js
+++ b/lib/rules/multiline-ternary.js
@@ -27,19 +27,22 @@ module.exports = {
                 enum: ["always", "always-multiline", "never"]
             }
         ],
+
         messages: {
             expectedTestCons: "Expected newline between test and consequent of ternary expression.",
             expectedConsAlt: "Expected newline between consequent and alternate of ternary expression.",
             unexpectedTestCons: "Unexpected newline between test and consequent of ternary expression.",
             unexpectedConsAlt: "Unexpected newline between consequent and alternate of ternary expression."
-        }
+        },
+
+        fixable: "whitespace"
     },
 
     create(context) {
+        const sourceCode = context.getSourceCode();
         const option = context.options[0];
         const multiline = option !== "never";
         const allowSingleLine = option === "always-multiline";
-        const sourceCode = context.getSourceCode();
 
         //--------------------------------------------------------------------------
         // Public
@@ -59,6 +62,8 @@ module.exports = {
                 const areTestAndConsequentOnSameLine = astUtils.isTokenOnSameLine(lastTokenOfTest, firstTokenOfConsequent);
                 const areConsequentAndAlternateOnSameLine = astUtils.isTokenOnSameLine(lastTokenOfConsequent, firstTokenOfAlternate);
 
+                const hasComments = !!sourceCode.getCommentsInside(node).length;
+
                 if (!multiline) {
                     if (!areTestAndConsequentOnSameLine) {
                         context.report({
@@ -67,7 +72,24 @@ module.exports = {
                                 start: firstTokenOfTest.loc.start,
                                 end: lastTokenOfTest.loc.end
                             },
-                            messageId: "unexpectedTestCons"
+                            messageId: "unexpectedTestCons",
+                            fix: fixer => {
+                                if (hasComments) {
+                                    return null;
+                                }
+                                const fixers = [];
+                                const areTestAndQuestionOnSameLine = astUtils.isTokenOnSameLine(lastTokenOfTest, questionToken);
+                                const areQuestionAndConsOnSameLine = astUtils.isTokenOnSameLine(questionToken, firstTokenOfConsequent);
+
+                                if (!areTestAndQuestionOnSameLine) {
+                                    fixers.push(fixer.removeRange([lastTokenOfTest.range[1], questionToken.range[0]]));
+                                }
+                                if (!areQuestionAndConsOnSameLine) {
+                                    fixers.push(fixer.removeRange([questionToken.range[1], firstTokenOfConsequent.range[0]]));
+                                }
+
+                                return fixers;
+                            }
                         });
                     }
 
@@ -78,7 +100,24 @@ module.exports = {
                                 start: firstTokenOfConsequent.loc.start,
                                 end: lastTokenOfConsequent.loc.end
                             },
-                            messageId: "unexpectedConsAlt"
+                            messageId: "unexpectedConsAlt",
+                            fix: fixer => {
+                                if (hasComments) {
+                                    return null;
+                                }
+                                const fixers = [];
+                                const areConsAndColonOnSameLine = astUtils.isTokenOnSameLine(lastTokenOfConsequent, colonToken);
+                                const areColonAndAltOnSameLine = astUtils.isTokenOnSameLine(colonToken, firstTokenOfAlternate);
+
+                                if (!areConsAndColonOnSameLine) {
+                                    fixers.push(fixer.removeRange([lastTokenOfConsequent.range[1], colonToken.range[0]]));
+                                }
+                                if (!areColonAndAltOnSameLine) {
+                                    fixers.push(fixer.removeRange([colonToken.range[1], firstTokenOfAlternate.range[0]]));
+                                }
+
+                                return fixers;
+                            }
                         });
                     }
                 } else {
@@ -93,7 +132,16 @@ module.exports = {
                                 start: firstTokenOfTest.loc.start,
                                 end: lastTokenOfTest.loc.end
                             },
-                            messageId: "expectedTestCons"
+                            messageId: "expectedTestCons",
+                            fix: fixer => (hasComments ? null : (
+                                fixer.replaceTextRange(
+                                    [
+                                        lastTokenOfTest.range[1],
+                                        questionToken.range[0]
+                                    ],
+                                    "\n"
+                                )
+                            ))
                         });
                     }
 
@@ -104,7 +152,16 @@ module.exports = {
                                 start: firstTokenOfConsequent.loc.start,
                                 end: lastTokenOfConsequent.loc.end
                             },
-                            messageId: "expectedConsAlt"
+                            messageId: "expectedConsAlt",
+                            fix: (fixer => (hasComments ? null : (
+                                fixer.replaceTextRange(
+                                    [
+                                        lastTokenOfConsequent.range[1],
+                                        colonToken.range[0]
+                                    ],
+                                    "\n"
+                                )
+                            )))
                         });
                     }
                 }
diff --git a/tests/lib/rules/multiline-ternary.js b/tests/lib/rules/multiline-ternary.js
index ff0f9d1535d..04698ae9513 100644
--- a/tests/lib/rules/multiline-ternary.js
+++ b/tests/lib/rules/multiline-ternary.js
@@ -116,6 +116,7 @@ ruleTester.run("multiline-ternary", rule, {
         // default "always"
         {
             code: "a ? b : c",
+            output: "a\n? b\n: c",
             errors: [{
                 messageId: "expectedTestCons",
                 line: 1,
@@ -129,6 +130,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : c",
+            output: "a\n? b\n: c",
             errors: [{
                 messageId: "expectedConsAlt",
                 line: 2,
@@ -137,6 +139,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b\n: c",
+            output: "a\n? b\n: c",
             errors: [{
                 messageId: "expectedTestCons",
                 line: 1,
@@ -145,6 +148,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b ? c : d) : e",
+            output: "a\n? (b\n? c\n: d)\n: e",
             errors: [{
                 messageId: "expectedTestCons",
                 line: 1,
@@ -170,6 +174,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b ? c : d) :\ne",
+            output: "a ?\n(b\n? c\n: d) :\ne",
             errors: [{
                 messageId: "expectedTestCons",
                 line: 2,
@@ -183,6 +188,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b\n? c\n: d) : e",
+            output: "a\n? (b\n? c\n: d)\n: e",
             errors: [{
                 messageId: "expectedTestCons",
                 line: 1,
@@ -198,6 +204,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b? c\n: d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             errors: [{
                 messageId: "expectedConsAlt",
                 line: 2,
@@ -213,6 +220,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c : d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             errors: [{
                 messageId: "expectedConsAlt",
                 line: 2,
@@ -228,6 +236,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c\n : d) : e",
+            output: "a ?\n(b\n? c\n : d)\n: e",
             errors: [{
                 messageId: "expectedConsAlt",
                 line: 2,
@@ -240,6 +249,7 @@ ruleTester.run("multiline-ternary", rule, {
         // "always"
         {
             code: "a ? b : c",
+            output: "a\n? b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -258,6 +268,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "f() ? a + b : c",
+            output: "f()\n? a + b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -276,6 +287,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : c",
+            output: "a\n? b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -285,6 +297,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b\n: c",
+            output: "a\n? b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -294,6 +307,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b ? c : d) : e",
+            output: "a\n? (b\n? c\n: d)\n: e",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -320,6 +334,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b ? c : d) :\ne",
+            output: "a ?\n(b\n? c\n: d) :\ne",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -334,6 +349,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b\n? c\n: d) : e",
+            output: "a\n? (b\n? c\n: d)\n: e",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -350,6 +366,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b? c\n: d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -366,6 +383,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c : d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -382,6 +400,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c\n : d) : e",
+            output: "a ?\n(b\n? c\n : d)\n: e",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -393,6 +412,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a\n) ? b\n: c",
+            output: "(a\n)\n? b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -404,6 +424,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "((a)\n) ? b\n: c",
+            output: "((a)\n)\n? b\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -415,6 +436,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (\nb)\n: c",
+            output: "a\n? (\nb)\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -426,6 +448,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (\n(b))\n: c",
+            output: "a\n? (\n(b))\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -437,6 +460,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? (b\n): c",
+            output: "a\n? (b\n)\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -448,6 +472,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? ((b)\n): c",
+            output: "a\n? ((b)\n)\n: c",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -459,6 +484,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : (\nc)",
+            output: "a\n? b\n: (\nc)",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -470,6 +496,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : (\n(c))",
+            output: "a\n? b\n: (\n(c))",
             options: ["always"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -481,6 +508,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a\n) ? (\nb\n) : (\nc)",
+            output: "(a\n)\n? (\nb\n)\n: (\nc)",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -499,6 +527,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "((a)\n) ? (\n(b)\n) : (\n(c))",
+            output: "((a)\n)\n? (\n(b)\n)\n: (\n(c))",
             options: ["always"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -519,6 +548,7 @@ ruleTester.run("multiline-ternary", rule, {
         // "always-multiline"
         {
             code: "a\n? b : c",
+            output: "a\n? b\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -528,6 +558,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b\n: c",
+            output: "a\n? b\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -537,6 +568,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a &&\nb ? c : d",
+            output: "a &&\nb\n? c\n: d",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -553,6 +585,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b +\nc : d",
+            output: "a\n? b +\nc\n: d",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -567,6 +600,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b : c +\nd",
+            output: "a\n? b\n: c +\nd",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -581,6 +615,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b ? c : d) : e",
+            output: "a ?\n(b ? c : d)\n: e",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -592,6 +627,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b ? c : d) :\ne",
+            output: "a\n? (b ? c : d) :\ne",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -601,6 +637,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b\n? c\n: d) : e",
+            output: "a\n? (b\n? c\n: d)\n: e",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -617,6 +654,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b ? c\n: d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -633,6 +671,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c : d) : e",
+            output: "a ?\n(b\n? c\n: d)\n: e",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -649,6 +688,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c\n : d) : e",
+            output: "a ?\n(b\n? c\n : d)\n: e",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -660,6 +700,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a\n) ? b\n: c",
+            output: "(a\n)\n? b\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -671,6 +712,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "((a)\n) ? b\n: c",
+            output: "((a)\n)\n? b\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -682,6 +724,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (\nb)\n: c",
+            output: "a\n? (\nb)\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -693,6 +736,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (\n(b))\n: c",
+            output: "a\n? (\n(b))\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -704,6 +748,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? (b\n): c",
+            output: "a\n? (b\n)\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -715,6 +760,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? ((b)\n): c",
+            output: "a\n? ((b)\n)\n: c",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -726,6 +772,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : (\nc)",
+            output: "a\n? b\n: (\nc)",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -737,6 +784,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n? b : (\n(c))",
+            output: "a\n? b\n: (\n(c))",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedConsAlt",
@@ -748,6 +796,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a\n) ? (\nb\n) : (\nc)",
+            output: "(a\n)\n? (\nb\n)\n: (\nc)",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -766,6 +815,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "((a)\n) ? (\n(b)\n) : (\n(c))",
+            output: "((a)\n)\n? (\n(b)\n)\n: (\n(c))",
             options: ["always-multiline"],
             errors: [{
                 messageId: "expectedTestCons",
@@ -786,6 +836,7 @@ ruleTester.run("multiline-ternary", rule, {
         // "never"
         {
             code: "a\n? b : c",
+            output: "a? b : c",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -795,6 +846,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? b\n: c",
+            output: "a ? b: c",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedConsAlt",
@@ -804,6 +856,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b ? c : d) :\ne",
+            output: "a ?(b ? c : d) :e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -820,6 +873,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b\n? c\n: d) : e",
+            output: "a ? (b? c: d) : e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -834,6 +888,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b? c\n: d) : e",
+            output: "a ?(b? c: d) : e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -848,6 +903,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c : d) : e",
+            output: "a ?(b? c : d) : e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -862,6 +918,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ?\n(b\n? c\n : d) : e",
+            output: "a ?(b? c: d) : e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -881,6 +938,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a ? (b\n? c\n: d)\n: e",
+            output: "a ? (b? c: d): e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedConsAlt",
@@ -902,6 +960,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "a\n?\n(b\n?\nc\n:\nd)\n:\ne",
+            output: "a?(b?c:d):e",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -928,6 +987,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a)\n ? b \n : (c)",
+            output: "(a)? b: (c)",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -946,6 +1006,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "(a)\n ? (b) \n : (c)",
+            output: "(a)? (b): (c)",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -964,6 +1025,7 @@ ruleTester.run("multiline-ternary", rule, {
         },
         {
             code: "((a))\n ? ((b)) \n : ((c))",
+            output: "((a))? ((b)): ((c))",
             options: ["never"],
             errors: [{
                 messageId: "unexpectedTestCons",
@@ -979,6 +1041,15 @@ ruleTester.run("multiline-ternary", rule, {
                 endLine: 2,
                 endColumn: 9
             }]
+        },
+
+        // https://github.com/eslint/eslint/pull/12982#discussion_r409120960
+        {
+            code: "a ? // comment\nb : c;",
+            output: null,
+            errors: [{
+                messageId: "expectedConsAlt"
+            }]
         }
     ]
 });