Single Sign-On (SSO) is an essential authentication method that makes access easier while enhancing security. Through enabling users to log in once to use many applications, SSO minimizes the hassle of dealing with numerous passwords, decreasing the risk of phishing, credential stuffing, and poor password usage. Organizations enjoy enhanced efficiency, centralized identity management, and increased compliance with security standards. Nonetheless, SSO can be a point of failure if not adequately secured. In order to prevent risks, companies should implement Multi-Factor Authentication (MFA), have strict session controls, and use continuous monitoring to identify and respond to potential security risks.