diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7917057a58..141d06b68b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ All notable changes to this project will be documented in this file. See [standa
 ### Bug Fixes
 
 * mixpanel timestamp in ms ([#2990](https://github.com/rudderlabs/rudder-transformer/issues/2990)) ([0da63a4](https://github.com/rudderlabs/rudder-transformer/commit/0da63a4e368e59d46c1eaa4a77d4ac81e686183a))
+* klaviyo: Event validation to be string before operating on it ([#2994](https://github.com/rudderlabs/rudder-transformer/issues/2994)) ([cd68d7c](https://github.com/rudderlabs/rudder-transformer/commit/cd68d7c4068588a325029e0cc523b74c3d3ccb1a))
 
 ## [1.53.0](https://github.com/rudderlabs/rudder-transformer/compare/v1.52.4...v1.53.0) (2024-01-08)
 
diff --git a/src/v0/destinations/klaviyo/transform.js b/src/v0/destinations/klaviyo/transform.js
index 9273b6a048..1d0df76835 100644
--- a/src/v0/destinations/klaviyo/transform.js
+++ b/src/v0/destinations/klaviyo/transform.js
@@ -36,6 +36,7 @@ const {
   handleRtTfSingleEventError,
   flattenJson,
   isNewStatusCodesAccepted,
+  validateEventName,
 } = require('../../util');
 const { JSON_MIME_TYPE, HTTP_STATUS_CODES } = require('../../util/constant');
 
@@ -156,7 +157,8 @@ const trackRequestHandler = (message, category, destination) => {
   const payload = {};
   const { privateApiKey, flattenProperties } = destination.Config;
   let event = get(message, 'event');
-  event = event ? event.trim().toLowerCase() : event;
+  validateEventName(event);
+  event = event.trim().toLowerCase();
   let attributes = {};
   if (ecomEvents.includes(event) && message.properties) {
     const eventName = eventNameMapping[event];
diff --git a/test/integrations/destinations/klaviyo/network.ts b/test/integrations/destinations/klaviyo/network.ts
index aa788a60da..d76d235c6f 100644
--- a/test/integrations/destinations/klaviyo/network.ts
+++ b/test/integrations/destinations/klaviyo/network.ts
@@ -1,75 +1,73 @@
 export const networkCallsData = [
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/v2/list/XUepkK/subscribe',
-            method: 'GET',
-        },
-        httpRes: {
-            status: 200
-        },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/v2/list/XUepkK/subscribe',
+      method: 'GET',
     },
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/v2/list/XUepkK/members',
-            method: 'GET',
-        },
-        httpRes: {
-            status: 200
-        },
+    httpRes: {
+      status: 200,
     },
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/profiles',
-            method: 'GET',
-            data: {
-                attributes: {
-                    email: "test3@rudderstack.com"
-                }
-            }
-        },
-        httpRes: {
-            status: 409,
-            data: {
-            }
-        },
+  },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/v2/list/XUepkK/members',
+      method: 'GET',
     },
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/profiles',
-            method: 'GET',
-        },
-        httpRes: {
-            status: 201,
-            data: {
-                data: {
-                    id: '01GW3PHVY0MTCDGS0A1612HARX',
-                    attributes: {}
-                },
-            }
-        },
+    httpRes: {
+      status: 200,
     },
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/profiles',
-            method: 'POST',
-            headers: { Authorization: 'Klaviyo-API-Key dummyPrivateApiKeyforfailure' }
-        },
-        httpRes: {
+  },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/profiles',
+      method: 'GET',
+      data: {
+        attributes: {
+          email: 'test3@rudderstack.com',
         },
+      },
+    },
+    httpRes: {
+      status: 409,
+      data: {},
     },
-    {
-        httpReq: {
-            url: 'https://a.klaviyo.com/api/profiles',
-            method: 'POST',
+  },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/profiles',
+      method: 'GET',
+    },
+    httpRes: {
+      status: 201,
+      data: {
+        data: {
+          id: '01GW3PHVY0MTCDGS0A1612HARX',
+          attributes: {},
         },
-        httpRes: {
-            status: 201,
-            data: {
-                data: {
-                    id: '01GW3PHVY0MTCDGS0A1612HARX',
-                    attributes: {}
-                },
-            }
+      },
+    },
+  },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/profiles',
+      method: 'POST',
+      headers: { Authorization: 'Klaviyo-API-Key dummyPrivateApiKeyforfailure' },
+    },
+    httpRes: {},
+  },
+  {
+    httpReq: {
+      url: 'https://a.klaviyo.com/api/profiles',
+      method: 'POST',
+    },
+    httpRes: {
+      status: 201,
+      data: {
+        data: {
+          id: '01GW3PHVY0MTCDGS0A1612HARX',
+          attributes: {},
         },
-    }
+      },
+    },
+  },
 ];
diff --git a/test/integrations/destinations/klaviyo/processor/data.ts b/test/integrations/destinations/klaviyo/processor/data.ts
index 2025957716..cd05ded315 100644
--- a/test/integrations/destinations/klaviyo/processor/data.ts
+++ b/test/integrations/destinations/klaviyo/processor/data.ts
@@ -1491,6 +1491,115 @@ export const data = [
 			}
 		}
 	},
+	{
+		"name": "klaviyo",
+		"description": "Track event call -> Invalid event i.e. sent as non-string",
+		"feature": "processor",
+		"module": "destination",
+		"version": "v0",
+		"input": {
+			"request": {
+				"body": [
+					{
+						"destination": {
+							"Config": {
+								"publicApiKey": "dummyPublicApiKey",
+								"privateApiKey": "dummyPrivateApiKey"
+							}
+						},
+						"message": {
+							"type": "track",
+							"event": { "name": "TestEven002" },
+							"sentAt": "2021-01-25T16:12:02.048Z",
+							"userId": "sajal12",
+							"channel": "mobile",
+							"context": {
+								"os": {
+									"name": "Android",
+									"version": "10"
+								},
+								"app": {
+									"name": "KlaviyoTest",
+									"build": "1",
+									"version": "1.0",
+									"namespace": "com.rudderstack.android.rudderstack.sampleAndroidApp"
+								},
+								"device": {
+									"id": "9c6bd77ea9da3e68",
+									"name": "raphaelin",
+									"type": "android",
+									"model": "Redmi K20 Pro",
+									"manufacturer": "Xiaomi"
+								},
+								"locale": "en-IN",
+								"screen": {
+									"width": 1080,
+									"height": 2210,
+									"density": 440
+								},
+								"traits": {
+									"id": "user@1",
+									"age": "22",
+									"name": "Test",
+									"email": "test@rudderstack.com",
+									"phone": "9112340375",
+									"anonymousId": "9c6bd77ea9da3e68",
+									"description": "Sample description"
+								},
+								"library": {
+									"name": "com.rudderstack.android.sdk.core",
+									"version": "1.0.2"
+								},
+								"network": {
+									"wifi": true,
+									"carrier": "airtel",
+									"cellular": true,
+									"bluetooth": false
+								},
+								"timezone": "Asia/Kolkata",
+								"userAgent": "Dalvik/2.1.0 (Linux; U; Android 10; Redmi K20 Pro MIUI/V12.0.4.0.QFKINXM)"
+							},
+							"rudderId": "b7b24f86-f7bf-46d8-b2b4-ccafc080239c",
+							"messageId": "1611588776408-ee5a3212-fbf9-4cbb-bbad-3ed0f7c6a2ce",
+							"properties": {
+								"PreviouslyVicePresident": true,
+								"YearElected": 1801,
+								"VicePresidents": [
+									"Aaron Burr",
+									"George Clinton"
+								],
+								"revenue": 3000
+							},
+							"anonymousId": "9c6bd77ea9da3e68",
+							"integrations": {
+								"All": true
+							},
+							"originalTimestamp": "2021-01-25T15:32:56.409Z"
+						}
+					}
+				]
+			}
+		},
+		"output": {
+			"response": {
+				"status": 200,
+				"body": [
+					{
+						"error": "Event is a required field and should be a string",
+						"statTags": {
+							"destType": "KLAVIYO",
+							"errorCategory": "dataValidation",
+							"errorType": "instrumentation",
+							"feature": "processor",
+							"implementation": "native",
+							"module": "destination",
+						},
+						"statusCode": 400
+					}
+				]
+			}
+		}
+	},
 	{
 		"name": "klaviyo",
 		"description": "Track event call, with make email or phone as primary identifier toggle on",