Beathard signed with the Jaguars' 53-man roster Wednesday.
Beathard was on the Dolphins' practice squad before the move and will provide quarterback depth for Jacksonville while Trevor Lawrence nurses a shoulder injury. The Iowa product was with the Jaguars during training camp and appeared in seven games for the team last season. If Lawrence is unable to play Sunday against the Vikings, Beathard would likely operate as the No. 2 quarterback, behind Mac Jones.