[Object] To enable a time before communication by way of a wireless network starts to be further reduced.[Solution] Provided is a terminal device including: an acquisition unit configured to acquire authentication information provided by another terminal device configured to perform mobile communication in a mobile communication network; and an authentication execution unit configured to perform an authentication procedure for connecting to a wireless network different from the mobile communication network by using the authentication information. The authentication information includes information provided by a subscriber identity module of the other terminal device or information generated based on the information. The acquisition unit acquires at least some of the authentication information before the authentication procedure starts.