The Master between series
Gordon Tipple
The Doctor Who TV movie brought the conflict between the Doctor and the Master back to screens, but it had to confront the old problem that the Master had already been defeated. The final episode of the Classic Era ended with the Master trapped on a planet being destroyed, and the 1996 film began with the concept that the Master had been killed, although for different reasons.
The version of the Master who was killed was played by Gordon Tipple. He was initially supposed to provide the opening narration, but that was changed to focus the story on the Doctor. Because of this, Tipple has no dialogue in the film and is only shown briefly. Nonetheless, he is credited to the part, and the Master's mortal remains took on a major role in the film when he refused to stay dead.
Eric Roberts
Though Gordon Tipple was the Master at the start of the TV movie, Eric Roberts played the part for the majority of it. Similar to how he claimed a new body in "The Keeper of Traken," the Master took over the body of a man named Bruce Gerhardt, using it to torment the Doctor throughout the rest of the movie.
Although Eric Roberts only ever got the chance to play the Master once on-screen, this version of the character does appear from time to time in the wider Doctor Who mediascape, particularly in his own and other characters' audio dramas.
Derek Jacobi
Derek Jacobi has a complicated relationship with the Master, because he played the part in two different settings, with dubious canonicity. He first took on the role in the 2003 Scream of the Shalka animated series, which was rejected by the revival's continuity. However, the 2024 episode "Rogue" depicted Richard E Grant as a valid version of the Doctor, which theoretically also canonizes Jacobi's Shalka Master.
Before that was brought back into the canon, however, Jacobi had his only live-action outing as the Master in the Series 3 episode "Utopia" (Episode 11). This version of the character, known in the fandom as the War Master, was initially introduced as Professor Yana, an eccentric genius attempting to save humanity. However, Martha Jones prompted him to open a chameleon arc that contained his true identity.
Sadly, the Master regenerated shortly after regaining his memories, keeping Jacobi from having the chance to truly play the character. But while he only appeared on-screen in the one episode, Jacobi has revisited the role nearly 50 times in audio dramas, primarily under the "War Master" run.