The Cowboys waived Gathers last week. The Browns announced that tight end Orson Charles was released in a corresponding roster move.
Dallas selected Gathers, a former Baylor basketball player, in the sixth round of the 2016 NFL Draft. His roster spot with the Cowboys was in jeopardy after 11-time Pro Bowler Jason Witten came out of retirement. Gathers also missed time in training camp due to an ankle injury.
If Gathers makes the Browns' 53-man roster, he will serve a one-game suspension this season. The league suspended him earlier this year for violating the NFL's substance abuse policy.
Gathers played in 15 regular-season games (four starts) with the Cowboys last season. He recorded three receptions for 45 yards.
The Baylor product joins a Browns tight end group that consists of David Njoku, Demetrius Harris, Seth DeValve and Pharaoh Brown.