Robert Carlyle (Redemption)

24: Carl Benton
Star Gate Universe: Dr. Nicholas Rush

Tony Todd

24: General Benjamin Juma
Star Gate SG-1: Lord Haikon
Andromeda: Captain Fehdman Metis
Star Trek Voyager: Unnamed Hirogen hunter
Star Trek DS9: Jake Sisko as adult in The Visitor
Star Trek TNG/DS9: Kurn

John Billingsley

24: Michael Latham
Star Trek Enterprise: Dr. Phlox

Kurtwood Smith

24: Senator Blaine Mayer
Star Trek Voyager: Annorax in Year of Hell

Jeffrey Nordling

24: Larry Moss
Star Trek DS9: Thana Los in Past Prologue

Mark Kiely

24: Edward Vossler
Star Trek Voyager: Lasca in Non Sequitur

Nick Toth

24: Edwin Ross
Babylon 5: Exeter in The Deconstruction of Fallen Stars

Annie Wersching

24: Renee Walker (seriously hot FBI agent)
Star Trek Enterprise: Liana in Oasis

Colm Feore

24: Henry Tailor
Battlestar Galactica: President Adar (First episode only)

Bob Gunton

24: Ethan Kanin
Star Trek TNG: Capt. Benjamin Maxwell (in The Wounded)

Ryan Cutrona

24: Admiral John Smith
Babylon 5: Sgt. Major Plug in GROPOS

John Rosenfeld

24: Kevin Aldridge
Star Trek Enterprise: Mark Latrelle in Silent Enemy

It’s also worth noting that co-executive producers and writers of 24 Redemption and season 7 is none other than Brannon Braga and Manny Coto, noted writers/producers from Star Trek TNG / Voyager / Enterprise.