Single Sign-On (SSO) is an essential authentication solution that drives security, user convenience, and IT efficiency. It allows users to log on once and access several applications, which prevents password fatigue and reduces risks such as phishing and credential stuffing. Organizations enjoy streamlined identity management, enhanced compliance with regulations, and reduced IT support costs. But SSO also becomes a single point of failure if not properly secured. Businesses should therefore institute Multi-Factor Authentication (MFA), ensure least privilege access, and apply real-time security monitoring to intercept and block attempts at unauthorized access.