Typically, when a user switches sessions between devices, the user authenticates the sessions by providing user account information, password, and/or pin code input or other credentials. However, when the user is frequently switching sessions between devices, authenticating sessions may result in the user reducing or even stopping switching across mobile devices. Systems and methods according to this disclosure provide automatic session roaming across mobile devices using proximity authentication. Upon detecting an indication to initiate session roaming, the source device automatically roams the session on the source device to a target device based on a proximity of the source device to the target device. The session is handed off from the source device to the target device as an authenticated user session.