diff --git a/packages/eslint-plugin/src/rules/key-spacing.ts b/packages/eslint-plugin/src/rules/key-spacing.ts
index 2562107ee050..2d4d3f5c11df 100644
--- a/packages/eslint-plugin/src/rules/key-spacing.ts
+++ b/packages/eslint-plugin/src/rules/key-spacing.ts
@@ -85,6 +85,15 @@ export default util.createRule<Options, MessageIds>({
       );
     }
 
+    function isApplicable(
+      node: TSESTree.Node,
+    ): node is KeyTypeNodeWithTypeAnnotation {
+      return (
+        isKeyTypeNode(node) &&
+        node.typeAnnotation.loc.start.line === node.loc.end.line
+      );
+    }
+
     /**
      * To handle index signatures, to get the whole text for the parameters
      */
@@ -281,7 +290,7 @@ export default util.createRule<Options, MessageIds>({
       }
 
       for (const node of group) {
-        if (!isKeyTypeNode(node)) {
+        if (!isApplicable(node)) {
           continue;
         }
         const { typeAnnotation } = node;
@@ -356,7 +365,7 @@ export default util.createRule<Options, MessageIds>({
           ? options.multiLine.mode
           : options.mode) ?? 'strict';
 
-      if (isKeyTypeNode(node)) {
+      if (isApplicable(node)) {
         checkBeforeColon(node, expectedWhitespaceBeforeColon, mode);
         checkAfterColon(node, expectedWhitespaceAfterColon, mode);
       }
diff --git a/packages/eslint-plugin/tests/rules/key-spacing.test.ts b/packages/eslint-plugin/tests/rules/key-spacing.test.ts
index 40206258671c..e7828e01ffe0 100644
--- a/packages/eslint-plugin/tests/rules/key-spacing.test.ts
+++ b/packages/eslint-plugin/tests/rules/key-spacing.test.ts
@@ -11,6 +11,48 @@ const ruleTester = new RuleTester({
 
 ruleTester.run('key-spacing', rule, {
   valid: [
+    // non-applicable
+    {
+      code: `
+interface X {
+  x:
+    | number
+    | string;
+}
+      `,
+      options: [{ align: 'value' }],
+    },
+    {
+      code: `
+interface X {
+  x:
+    | number
+    | string;
+}
+      `,
+      options: [{}],
+    },
+    {
+      code: `
+interface X {
+  abcdef: string;
+  x:
+    | number
+    | string;
+  defgh: string;
+}
+      `,
+      options: [{ align: 'value' }],
+    },
+    {
+      code: `
+interface X {
+  x:
+    | number; abcd: string;
+}
+      `,
+      options: [{ align: 'value' }],
+    },
     // align: value
     {
       code: `