diff --git a/packages/core/src/baseclient.ts b/packages/core/src/baseclient.ts
index d24a168614de..aa292e44cf33 100644
--- a/packages/core/src/baseclient.ts
+++ b/packages/core/src/baseclient.ts
@@ -100,9 +100,6 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
   /** Array of set up integrations. */
   protected _integrations: IntegrationIndex;
 
-  /** Indicates whether this client's integrations have been set up. */
-  protected _integrationsInitialized: boolean;
-
   /** Number of calls being processed */
   protected _numProcessing: number;
 
@@ -122,7 +119,6 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
   protected constructor(options: O) {
     this._options = options;
     this._integrations = {};
-    this._integrationsInitialized = false;
     this._numProcessing = 0;
     this._outcomes = {};
     this._hooks = {};
@@ -303,16 +299,6 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
     this._eventProcessors.push(eventProcessor);
   }
 
-  /**
-   * This is an internal function to setup all integrations that should run on the client.
-   * @deprecated Use `client.init()` instead.
-   */
-  public setupIntegrations(forceInitialize?: boolean): void {
-    if ((forceInitialize && !this._integrationsInitialized) || (this._isEnabled() && !this._integrationsInitialized)) {
-      this._setupIntegrations();
-    }
-  }
-
   /** @inheritdoc */
   public init(): void {
     if (this._isEnabled()) {
@@ -533,9 +519,6 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
     const { integrations } = this._options;
     this._integrations = setupIntegrations(this, integrations);
     afterSetupIntegrations(this, integrations);
-
-    // TODO v8: We don't need this flag anymore
-    this._integrationsInitialized = true;
   }
 
   /** Updates existing session based on the provided event */
diff --git a/packages/core/src/hub.ts b/packages/core/src/hub.ts
index 98c4f1f70b6a..39e9f7de1ec1 100644
--- a/packages/core/src/hub.ts
+++ b/packages/core/src/hub.ts
@@ -165,10 +165,8 @@ export class Hub implements HubInterface {
     const top = this.getStackTop();
     top.client = client;
     top.scope.setClient(client);
-    // eslint-disable-next-line deprecation/deprecation
-    if (client && client.setupIntegrations) {
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
+    if (client) {
+      client.init();
     }
   }
 
diff --git a/packages/core/test/lib/base.test.ts b/packages/core/test/lib/base.test.ts
index 6be7b6e097a2..0f789e2da169 100644
--- a/packages/core/test/lib/base.test.ts
+++ b/packages/core/test/lib/base.test.ts
@@ -1471,18 +1471,6 @@ describe('BaseClient', () => {
       global.__SENTRY__ = {};
     });
 
-    test('sets up each integration on `setupIntegrations` call', () => {
-      expect.assertions(2);
-
-      const options = getDefaultTestClientOptions({ dsn: PUBLIC_DSN, integrations: [new TestIntegration()] });
-      const client = new TestClient(options);
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
-
-      expect(Object.keys((client as any)._integrations).length).toEqual(1);
-      expect(client.getIntegrationByName(TestIntegration.id)).toBeTruthy();
-    });
-
     test('sets up each integration on `init` call', () => {
       expect.assertions(2);
 
@@ -1494,18 +1482,6 @@ describe('BaseClient', () => {
       expect(client.getIntegrationByName(TestIntegration.id)).toBeTruthy();
     });
 
-    test('skips installation for `setupIntegrations()` if DSN is not provided', () => {
-      expect.assertions(2);
-
-      const options = getDefaultTestClientOptions({ integrations: [new TestIntegration()] });
-      const client = new TestClient(options);
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
-
-      expect(Object.keys((client as any)._integrations).length).toEqual(0);
-      expect(client.getIntegrationByName(TestIntegration.id)).toBeFalsy();
-    });
-
     test('skips installation for `init()` if DSN is not provided', () => {
       expect.assertions(2);
 
@@ -1517,22 +1493,6 @@ describe('BaseClient', () => {
       expect(client.getIntegrationByName(TestIntegration.id)).toBeFalsy();
     });
 
-    test('skips installation for `setupIntegrations()` if `enabled` is set to `false`', () => {
-      expect.assertions(2);
-
-      const options = getDefaultTestClientOptions({
-        dsn: PUBLIC_DSN,
-        enabled: false,
-        integrations: [new TestIntegration()],
-      });
-      const client = new TestClient(options);
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
-
-      expect(Object.keys((client as any)._integrations).length).toEqual(0);
-      expect(client.getIntegrationByName(TestIntegration.id)).toBeFalsy();
-    });
-
     test('skips installation for `init()` if `enabled` is set to `false`', () => {
       expect.assertions(2);
 
@@ -1548,29 +1508,6 @@ describe('BaseClient', () => {
       expect(client.getIntegrationByName(TestIntegration.id)).toBeFalsy();
     });
 
-    test('skips installation if integrations are already installed', () => {
-      expect.assertions(4);
-
-      const options = getDefaultTestClientOptions({ dsn: PUBLIC_DSN, integrations: [new TestIntegration()] });
-      const client = new TestClient(options);
-      // note: not the `Client` method `setupIntegrations`, but the free-standing function which that method calls
-      const setupIntegrationsHelper = jest.spyOn(integrationModule, 'setupIntegrations');
-
-      // it should install the first time, because integrations aren't yet installed...
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
-
-      expect(Object.keys((client as any)._integrations).length).toEqual(1);
-      expect(client.getIntegrationByName(TestIntegration.id)).toBeTruthy();
-      expect(setupIntegrationsHelper).toHaveBeenCalledTimes(1);
-
-      // ...but it shouldn't try to install a second time
-      // eslint-disable-next-line deprecation/deprecation
-      client.setupIntegrations();
-
-      expect(setupIntegrationsHelper).toHaveBeenCalledTimes(1);
-    });
-
     test('does not add integrations twice when calling `init` multiple times', () => {
       const options = getDefaultTestClientOptions({ dsn: PUBLIC_DSN, integrations: [new TestIntegration()] });
       const client = new TestClient(options);
diff --git a/packages/types/src/client.ts b/packages/types/src/client.ts
index 6be08e8652e1..a42845813246 100644
--- a/packages/types/src/client.ts
+++ b/packages/types/src/client.ts
@@ -139,12 +139,6 @@ export interface Client<O extends ClientOptions = ClientOptions> {
    * */
   addIntegration(integration: Integration): void;
 
-  /**
-   * This is an internal function to setup all integrations that should run on the client.
-   * @deprecated Use `client.init()` instead.
-   */
-  setupIntegrations(forceInitialize?: boolean): void;
-
   /**
    * Initialize this client.
    * Call this after the client was set on a scope.