diff --git a/.changeset/shaggy-melons-destroy.md b/.changeset/shaggy-melons-destroy.md
new file mode 100644
index 0000000000..d202cab6cd
--- /dev/null
+++ b/.changeset/shaggy-melons-destroy.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+Skip adding entries to the `entities_search` table if their `key` exceeds a length limit.
diff --git a/plugins/catalog-backend/src/database/search.test.ts b/plugins/catalog-backend/src/database/search.test.ts
index c6793cbdf4..656da8b6f5 100644
--- a/plugins/catalog-backend/src/database/search.test.ts
+++ b/plugins/catalog-backend/src/database/search.test.ts
@@ -101,6 +101,12 @@ describe('search', () => {
       expect(output).toEqual([{ entity_id: 'eid', key: 'foo', value: 'bar' }]);
     });
 
+    it('skips very large keys', () => {
+      const input = [{ key: 'a'.repeat(10000), value: 'foo' }];
+      const output = mapToRows(input, 'eid');
+      expect(output).toEqual([]);
+    });
+
     it('skips very large values', () => {
       const input = [{ key: 'foo', value: 'a'.repeat(10000) }];
       const output = mapToRows(input, 'eid');
diff --git a/plugins/catalog-backend/src/database/search.ts b/plugins/catalog-backend/src/database/search.ts
index 9e58d2468b..67b6d14b4f 100644
--- a/plugins/catalog-backend/src/database/search.ts
+++ b/plugins/catalog-backend/src/database/search.ts
@@ -31,6 +31,7 @@ const SPECIAL_KEYS = [
 // The maximum length allowed for search values. These columns are indexed, and
 // database engines do not like to index on massive values. For example,
 // postgres will balk after 8191 byte line sizes.
+const MAX_KEY_LENGTH = 200;
 const MAX_VALUE_LENGTH = 200;
 
 type Kv = {
@@ -136,7 +137,7 @@ export function mapToRows(
       result.push({ entity_id: entityId, key, value: null });
     } else {
       const value = String(rawValue).toLowerCase();
-      if (value.length <= MAX_VALUE_LENGTH) {
+      if (key.length <= MAX_KEY_LENGTH && value.length <= MAX_VALUE_LENGTH) {
         result.push({ entity_id: entityId, key, value });
       }
     }
diff --git a/plugins/catalog-backend/src/next/search.test.ts b/plugins/catalog-backend/src/next/search.test.ts
index 2e0b07b4a9..be896319b7 100644
--- a/plugins/catalog-backend/src/next/search.test.ts
+++ b/plugins/catalog-backend/src/next/search.test.ts
@@ -104,6 +104,12 @@ describe('search', () => {
       expect(output).toEqual([{ entity_id: 'eid', key: 'foo', value: 'bar' }]);
     });
 
+    it('skips very large keys', () => {
+      const input = [{ key: 'a'.repeat(10000), value: 'foo' }];
+      const output = mapToRows(input, 'eid');
+      expect(output).toEqual([]);
+    });
+
     it('skips very large values', () => {
       const input = [{ key: 'foo', value: 'a'.repeat(10000) }];
       const output = mapToRows(input, 'eid');
diff --git a/plugins/catalog-backend/src/next/search.ts b/plugins/catalog-backend/src/next/search.ts
index 383b29fd70..0681bffa17 100644
--- a/plugins/catalog-backend/src/next/search.ts
+++ b/plugins/catalog-backend/src/next/search.ts
@@ -43,6 +43,7 @@ const SPECIAL_KEYS = [
 // The maximum length allowed for search values. These columns are indexed, and
 // database engines do not like to index on massive values. For example,
 // postgres will balk after 8191 byte line sizes.
+const MAX_KEY_LENGTH = 200;
 const MAX_VALUE_LENGTH = 200;
 
 type Kv = {
@@ -145,7 +146,7 @@ export function mapToRows(input: Kv[], entityId: string): DbSearchRow[] {
       result.push({ entity_id: entityId, key, value: null });
     } else {
       const value = String(rawValue).toLocaleLowerCase('en-US');
-      if (value.length <= MAX_VALUE_LENGTH) {
+      if (key.length <= MAX_KEY_LENGTH && value.length <= MAX_VALUE_LENGTH) {
         result.push({ entity_id: entityId, key, value });
       }
     }