diff --git a/packages/eslint-plugin/src/util/collectUnusedVariables.ts b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
index dbe749e62900..cd215124d64c 100644
--- a/packages/eslint-plugin/src/util/collectUnusedVariables.ts
+++ b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
@@ -1,6 +1,7 @@
 import {
   ImplicitLibVariable,
   ScopeType,
+  Variable,
   Visitor,
 } from '@typescript-eslint/scope-manager';
 import type { TSESTree } from '@typescript-eslint/utils';
@@ -10,6 +11,7 @@ import {
   ESLintUtils,
   TSESLint,
 } from '@typescript-eslint/utils';
+import { isDefinitionFile } from './misc';
 
 class UnusedVarsVisitor<
   MessageIds extends string,
@@ -22,6 +24,7 @@ class UnusedVarsVisitor<
 
   readonly #scopeManager: TSESLint.Scope.ScopeManager;
   // readonly #unusedVariables = new Set<TSESLint.Scope.Variable>();
+  readonly #isDefinitionFile: boolean;
 
   private constructor(context: TSESLint.RuleContext<MessageIds, Options>) {
     super({
@@ -32,6 +35,8 @@ class UnusedVarsVisitor<
       context.sourceCode.scopeManager,
       'Missing required scope manager',
     );
+
+    this.#isDefinitionFile = isDefinitionFile(context.filename);
   }
 
   public static collectUnusedVariables<
@@ -60,7 +65,12 @@ class UnusedVarsVisitor<
     scope: TSESLint.Scope.Scope,
     unusedVariables = new Set<TSESLint.Scope.Variable>(),
   ): ReadonlySet<TSESLint.Scope.Variable> {
-    for (const variable of scope.variables) {
+    const implicitlyExported = allVariablesImplicitlyExported(
+      scope,
+      this.#isDefinitionFile,
+    );
+
+    for (const variable of implicitlyExported ? [] : scope.variables) {
       if (
         // skip function expression names,
         scope.functionExpressionScope ||
@@ -438,6 +448,47 @@ function isExported(variable: TSESLint.Scope.Variable): boolean {
   });
 }
 
+function allVariablesImplicitlyExported(
+  scope: TSESLint.Scope.Scope,
+  isDefinitionFile: boolean,
+): boolean {
+  // TODO: does this also happen in ambient module declarations?
+  if (
+    !isDefinitionFile ||
+    !(
+      scope.type === ScopeType.tsModule ||
+      scope.type === ScopeType.module ||
+      scope.type === ScopeType.global
+    )
+  ) {
+    return false;
+  }
+
+  // TODO: test modules, globals
+  // TODO: look for `export {}`
+
+  function isExportImportEquals(variable: Variable): boolean {
+    for (const def of variable.defs) {
+      if (
+        def.type === TSESLint.Scope.DefinitionType.ImportBinding &&
+        def.node.type === AST_NODE_TYPES.TSImportEqualsDeclaration &&
+        def.node.parent.type === AST_NODE_TYPES.ExportNamedDeclaration
+      ) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  for (const variable of scope.variables) {
+    if (isExported(variable) && !isExportImportEquals(variable)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 const LOGICAL_ASSIGNMENT_OPERATORS = new Set(['&&=', '||=', '??=']);
 
 /**
diff --git a/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts b/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
index 04c218b7631e..8827b82f30e2 100644
--- a/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
@@ -1123,6 +1123,72 @@ export namespace Bar {
   export import TheFoo = Foo;
 }
     `,
+    `
+const foo = 1;
+export = foo;
+    `,
+    `
+const Foo = 1;
+interface Foo {
+  bar: string;
+}
+export = Foo;
+    `,
+    `
+interface Foo {
+  bar: string;
+}
+export = Foo;
+    `,
+    `
+type Foo = 1;
+export = Foo;
+    `,
+    `
+type Foo = 1;
+export = {} as Foo;
+    `,
+    `
+declare module 'foo' {
+  type Foo = 1;
+  export = Foo;
+}
+    `,
+    `
+namespace Foo {
+  export const foo = 1;
+}
+export namespace Bar {
+  export import TheFoo = Foo;
+}
+    `,
+    // https://github.com/typescript-eslint/typescript-eslint/issues/2867
+    {
+      code: `
+export namespace Foo {
+  const foo: 1234;
+}
+      `,
+      filename: 'foo.d.ts',
+    },
+    {
+      code: `
+export namespace Foo {
+  export import Bar = Something.Bar;
+  const foo: 1234;
+}
+      `,
+      filename: 'foo.d.ts',
+    },
+    {
+      code: `
+declare module 'foo' {
+  export import Bar = Something.Bar;
+  const foo: 1234;
+}
+      `,
+      filename: 'foo.d.ts',
+    },
   ],
 
   invalid: [
@@ -1950,5 +2016,80 @@ export namespace Bar {
         },
       ],
     },
+    // https://github.com/typescript-eslint/typescript-eslint/issues/2867
+    {
+      code: `
+export namespace Foo {
+  const foo: 1234;
+  export const bar: string;
+  export namespace NS {
+    const baz: 1234;
+  }
+}
+      `,
+      filename: 'foo.d.ts',
+      errors: [
+        {
+          messageId: 'unusedVar',
+          line: 3,
+          column: 9,
+          data: {
+            varName: 'foo',
+            action: 'defined',
+            additional: '',
+          },
+        },
+      ],
+    },
+    {
+      code: `
+export namespace Foo {
+  export import Bar = Something.Bar;
+  const foo: 1234;
+  export const bar: string;
+  export namespace NS {
+    const baz: 1234;
+  }
+}
+      `,
+      filename: 'foo.d.ts',
+      errors: [
+        {
+          messageId: 'unusedVar',
+          line: 4,
+          column: 9,
+          data: {
+            varName: 'foo',
+            action: 'defined',
+            additional: '',
+          },
+        },
+      ],
+    },
+    {
+      code: `
+declare module 'foo' {
+  export import Bar = Something.Bar;
+  const foo: 1234;
+  export const bar: string;
+  export namespace NS {
+    const baz: 1234;
+  }
+}
+      `,
+      filename: 'foo.d.ts',
+      errors: [
+        {
+          messageId: 'unusedVar',
+          line: 4,
+          column: 9,
+          data: {
+            varName: 'foo',
+            action: 'defined',
+            additional: '',
+          },
+        },
+      ],
+    },
   ],
 });