An information distribution apparatus includes: a user information receiving unit configured to receive user information from user devices that respective users have, the user information including at least one of user-captured images and positional information of the users, and user IDs of the users; a user specifying unit configured to specify at least one user from a plurality of pieces of user information; an other user extraction unit configured to extract at least one other user who is present near the specified user based on at least one of the user-captured images and the positional information of the user; a related user group information generation unit configured to generate related user group information in which at least one of the pieces of user information is associated with at least one of pieces of other user information.