The disclosed computer-implemented method for categorizing web applications based on age restrictions in online content policies may include (i) accessing a web application associated with a group of application pages, (ii) determining policy data for accessing content from the web application in the application pages, (iii) extracting one or more age restrictions for accessing the web application from the policy data, and (iv) performing a security action that prevents underage access to the web application based on the age restrictions. Various other methods, systems, and computer-readable media are also disclosed.