Michael Dorn(I)

Made a grand total of 289 "Star Trek" appearances. He appeared in 175 of the 178 episodes of Jornada nas Estrelas: A Nova Geração (1987), 102 of the 176 episodes of Jornada nas Estrelas: Deep Space Nine (1993) Jornada nas Estrelas VI: A Terra Desconhecida (1991), Jornada nas Estrelas: Generations (1994), Jornada nas Estrelas: Primeiro Contato (1996), Jornada nas Estrelas: Insurreição (1998), Jornada Nas Estrelas: Nêmesis (2002) and Star Trek: Picard (2020). He also directed the following episodes: In the Cards (1997), Inquisition (1998), When It Rains... (1999) and Two Days and Two Nights (2002). The 284 episodes of Star Trek he appeared in means he has appeared in more episodes of Sci-Fi Television than any other actor.

But now they have the series down to a real science where it's about an hour.