Sheppard appeared in several episodes of different series of Star Trek, notably The Next Generation's "The Schizoid Man" and Voyager's "Bliss".

Sheppard appeared in two roles on the science-fiction series Babylon 5, in the episode titled "Soul Hunter", playing the eponymous character and also played Narn war leader G'Sten, an uncle of main character G'Kar, in "The Long Twilight Struggle".

[4] He appeared in the opening episode of series six of Doctor Who, "The Impossible Astronaut", playing the character Canton Everett Delaware III.

[4] In December 2009, Sheppard voiced the part of Santa in Disney's Christmas special Prep & Landing.

He narrated the introductions and mission briefings for the first four installments of the Medal of Honor video-game series.