The disclosed computer-implemented method for enforcing access-control policies may include (i) determining that a user is attempting to access a controlled device that is subject to an access-control policy, (ii) locating at least one additional device that is in physical proximity to the controlled device, (iii) acquiring context information from the additional device that provides information about the identity of the user, (iv) establishing the identity of the user based on the context information acquired from the additional device, and (v) enforcing the access-control policy based on the identity of the user. Various other methods, systems, and computer-readable media are also disclosed.