Modern enterprises are grappling with a significant authentication challenge, as they manage an average of 371 SaaS applications and face threats from credential-based attacks, which account for 80% of web application security incidents. Implementing Single Sign-On (SSO) is crucial for enhancing both security and user experience; however, if poorly executed, it can create vulnerabilities, as demonstrated by high-profile breaches like Microsoft's OAuth exploitation and Oracle Cloud's data breach. To address these risks, organizations are advised to adopt best practices such as OWASP-compliant token validation, phishing-resistant authentication, and comprehensive session management. The global SSO market is expected to grow significantly, reaching $9.4 billion by 2030. With evolving threats such as AI-powered attacks, deepfake authentication attempts, and regulatory shifts towards digital identity wallets, organizations must also adopt advanced monitoring and audit logging to detect threats early. Clerk, Auth0, and Okta are among the platforms offering robust solutions for SSO integration, providing varying levels of support for React applications, extensive protocol support, and advanced monitoring capabilities. As the cybersecurity landscape continues to evolve, adopting Zero Trust architecture, passwordless authentication, and AI security monitoring are key strategies for future-proofing identity management systems.