A computer-implemented method for verifying user identities may include (1) identifying a request to ascertain whether a user account corresponds to a physical person, and, in response to the request, (2) identifying a password vault configured to store login information for at least one third-party Internet site for the user account, the third-party Internet site requiring a physical validation factor to log in to the third-party Internet site, (3) determining, based at least in part on the login information for the third-party Internet site, that the user account corresponds to the physical person, and (4) responding to the request with an indicator that the user account corresponds to the physical person. Various other methods, systems, and computer-readable media are also disclosed.