diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f865d2fa58f..2f7332c181e 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -31013,6 +31013,18 @@ namespace ts {
             return tryCast(getRootDeclaration(node), isParameter);
         }
 
+        function isValidUnusedLocalDeclaration(declaration: Declaration): boolean {
+            if (isBindingElement(declaration) && isIdentifierThatStartsWithUnderscore(declaration.name)) {
+                return !!findAncestor(declaration.parent, ancestor =>
+                    isArrayBindingPattern(ancestor) || isVariableDeclaration(ancestor) || isVariableDeclarationList(ancestor) ? false :
+                        isForOfStatement(ancestor) ? true : "quit"
+                );
+            }
+
+            return isAmbientModule(declaration) ||
+                (isVariableDeclaration(declaration) && isForInOrOfStatement(declaration.parent.parent) || isImportedDeclaration(declaration)) && isIdentifierThatStartsWithUnderscore(declaration.name!);
+        }
+
         function checkUnusedLocalsAndParameters(nodeWithLocals: Node, addDiagnostic: AddUnusedDiagnostic): void {
             // Ideally we could use the ImportClause directly as a key, but must wait until we have full ES6 maps. So must store key along with value.
             const unusedImports = createMap<[ImportClause, ImportedDeclaration[]]>();
@@ -31026,8 +31038,7 @@ namespace ts {
                 }
 
                 for (const declaration of local.declarations) {
-                    if (isAmbientModule(declaration) ||
-                        (isVariableDeclaration(declaration) && isForInOrOfStatement(declaration.parent.parent) || isImportedDeclaration(declaration)) && isIdentifierThatStartsWithUnderscore(declaration.name!)) {
+                    if (isValidUnusedLocalDeclaration(declaration)) {
                         continue;
                     }
 
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.js b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.js
new file mode 100644
index 00000000000..0c08ba84193
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.js
@@ -0,0 +1,28 @@
+//// [unusedVariablesWithUnderscoreInForOfLoop.ts]
+function f() {
+    for (const [_a, b] of [['key', 1]]) {
+        console.log(b);
+    }
+
+    for (const [a, _b] of [['key', 1]]) {
+        console.log(a);
+    }
+
+    for (const [_a, _b] of [['key', 1]]) {}
+}
+
+
+//// [unusedVariablesWithUnderscoreInForOfLoop.js]
+function f() {
+    for (var _i = 0, _c = [['key', 1]]; _i < _c.length; _i++) {
+        var _d = _c[_i], _a = _d[0], b = _d[1];
+        console.log(b);
+    }
+    for (var _e = 0, _f = [['key', 1]]; _e < _f.length; _e++) {
+        var _g = _f[_e], a = _g[0], _b = _g[1];
+        console.log(a);
+    }
+    for (var _h = 0, _j = [['key', 1]]; _h < _j.length; _h++) {
+        var _k = _j[_h], _a = _k[0], _b = _k[1];
+    }
+}
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.symbols b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.symbols
new file mode 100644
index 00000000000..d6c97536d3b
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.symbols
@@ -0,0 +1,31 @@
+=== tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop.ts ===
+function f() {
+>f : Symbol(f, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 0, 0))
+
+    for (const [_a, b] of [['key', 1]]) {
+>_a : Symbol(_a, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 1, 16))
+>b : Symbol(b, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 1, 19))
+
+        console.log(b);
+>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
+>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>b : Symbol(b, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 1, 19))
+    }
+
+    for (const [a, _b] of [['key', 1]]) {
+>a : Symbol(a, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 5, 16))
+>_b : Symbol(_b, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 5, 18))
+
+        console.log(a);
+>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
+>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>a : Symbol(a, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 5, 16))
+    }
+
+    for (const [_a, _b] of [['key', 1]]) {}
+>_a : Symbol(_a, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 9, 16))
+>_b : Symbol(_b, Decl(unusedVariablesWithUnderscoreInForOfLoop.ts, 9, 19))
+}
+
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.types b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.types
new file mode 100644
index 00000000000..3ba565b7914
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop.types
@@ -0,0 +1,45 @@
+=== tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop.ts ===
+function f() {
+>f : () => void
+
+    for (const [_a, b] of [['key', 1]]) {
+>_a : string | number
+>b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+
+        console.log(b);
+>console.log(b) : void
+>console.log : (message?: any, ...optionalParams: any[]) => void
+>console : Console
+>log : (message?: any, ...optionalParams: any[]) => void
+>b : string | number
+    }
+
+    for (const [a, _b] of [['key', 1]]) {
+>a : string | number
+>_b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+
+        console.log(a);
+>console.log(a) : void
+>console.log : (message?: any, ...optionalParams: any[]) => void
+>console : Console
+>log : (message?: any, ...optionalParams: any[]) => void
+>a : string | number
+    }
+
+    for (const [_a, _b] of [['key', 1]]) {}
+>_a : string | number
+>_b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+}
+
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.errors.txt b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.errors.txt
new file mode 100644
index 00000000000..fa8b7d9d55c
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.errors.txt
@@ -0,0 +1,23 @@
+tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts(2,21): error TS6133: 'b' is declared but its value is never read.
+tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts(4,17): error TS6133: 'a' is declared but its value is never read.
+tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts(6,17): error TS6133: 'a' is declared but its value is never read.
+tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts(6,20): error TS6133: 'b' is declared but its value is never read.
+
+
+==== tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts (4 errors) ====
+    function f() {
+        for (const [_a, b] of [['key', 1]]) {}
+                        ~
+!!! error TS6133: 'b' is declared but its value is never read.
+    
+        for (const [a, _b] of [['key', 1]]) {}
+                    ~
+!!! error TS6133: 'a' is declared but its value is never read.
+    
+        for (const [a, b] of [['key', 1]]) {}
+                    ~
+!!! error TS6133: 'a' is declared but its value is never read.
+                       ~
+!!! error TS6133: 'b' is declared but its value is never read.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.js b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.js
new file mode 100644
index 00000000000..bb5ecbfe974
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.js
@@ -0,0 +1,22 @@
+//// [unusedVariablesWithUnderscoreInForOfLoop1.ts]
+function f() {
+    for (const [_a, b] of [['key', 1]]) {}
+
+    for (const [a, _b] of [['key', 1]]) {}
+
+    for (const [a, b] of [['key', 1]]) {}
+}
+
+
+//// [unusedVariablesWithUnderscoreInForOfLoop1.js]
+function f() {
+    for (var _i = 0, _c = [['key', 1]]; _i < _c.length; _i++) {
+        var _d = _c[_i], _a = _d[0], b = _d[1];
+    }
+    for (var _e = 0, _f = [['key', 1]]; _e < _f.length; _e++) {
+        var _g = _f[_e], a = _g[0], _b = _g[1];
+    }
+    for (var _h = 0, _j = [['key', 1]]; _h < _j.length; _h++) {
+        var _k = _j[_h], a = _k[0], b = _k[1];
+    }
+}
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.symbols b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.symbols
new file mode 100644
index 00000000000..b98293944af
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts ===
+function f() {
+>f : Symbol(f, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 0, 0))
+
+    for (const [_a, b] of [['key', 1]]) {}
+>_a : Symbol(_a, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 1, 16))
+>b : Symbol(b, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 1, 19))
+
+    for (const [a, _b] of [['key', 1]]) {}
+>a : Symbol(a, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 3, 16))
+>_b : Symbol(_b, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 3, 18))
+
+    for (const [a, b] of [['key', 1]]) {}
+>a : Symbol(a, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 5, 16))
+>b : Symbol(b, Decl(unusedVariablesWithUnderscoreInForOfLoop1.ts, 5, 18))
+}
+
diff --git a/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.types b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.types
new file mode 100644
index 00000000000..100e8719148
--- /dev/null
+++ b/tests/baselines/reference/unusedVariablesWithUnderscoreInForOfLoop1.types
@@ -0,0 +1,29 @@
+=== tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts ===
+function f() {
+>f : () => void
+
+    for (const [_a, b] of [['key', 1]]) {}
+>_a : string | number
+>b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+
+    for (const [a, _b] of [['key', 1]]) {}
+>a : string | number
+>_b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+
+    for (const [a, b] of [['key', 1]]) {}
+>a : string | number
+>b : string | number
+>[['key', 1]] : (string | number)[][]
+>['key', 1] : (string | number)[]
+>'key' : "key"
+>1 : 1
+}
+
diff --git a/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop.ts b/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop.ts
new file mode 100644
index 00000000000..064e1971ead
--- /dev/null
+++ b/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop.ts
@@ -0,0 +1,13 @@
+//@noUnusedLocals:true
+
+function f() {
+    for (const [_a, b] of [['key', 1]]) {
+        console.log(b);
+    }
+
+    for (const [a, _b] of [['key', 1]]) {
+        console.log(a);
+    }
+
+    for (const [_a, _b] of [['key', 1]]) {}
+}
diff --git a/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts b/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts
new file mode 100644
index 00000000000..0848f20d34a
--- /dev/null
+++ b/tests/cases/compiler/unusedVariablesWithUnderscoreInForOfLoop1.ts
@@ -0,0 +1,9 @@
+//@noUnusedLocals:true
+
+function f() {
+    for (const [_a, b] of [['key', 1]]) {}
+
+    for (const [a, _b] of [['key', 1]]) {}
+
+    for (const [a, b] of [['key', 1]]) {}
+}