Mickey 17 movie cast and plot explained starts with Bong Joon Ho sci-fi bench: Robert Pattinson leads as Mickey Barnes across clone iterations with Naomi Ackie, Steven Yeun, Mark Ruffalo, and Toni Collette in Niflheim expedition roles.

Robert Pattinson plays both Mickey 17 and the aggressive Mickey 18 printed while 17 was presumed dead. Variety reported Pattinson as Bong first choice — he improvised iteration 18 lines and used distinct accents for each clone.

Steven Yeun plays pilot Timo, the lead unreliable friend who leaves him to die in a fissure. Naomi Ackie is security agent Nasha — the love interest who later leads the colony after Marshall falls.

Mark Ruffalo leads as Kenneth Marshall, the authoritarian expedition chief with sinister Niflheim plans. Toni Collette plays his controlling wife Ylfa — both joined the cast in May 2022 per Hollywood Reporter.

Cameron Britton heads the Science Team as Arkady; Patsy Ferran plays Dorothy. Anamaria Vartolomei is Kai Katz, Stephen Park is Zeke, and Daniel Henshall is Preston — the Niflheim support roster.