- James McAvoy as Professor Charles Xavier / Professor X[1]
- Michael Fassbender as Erik Lehnsherr / Magneto[1]
- Jennifer Lawrence as Raven Darkhölme / Mystique[1]
- Nicholas Hoult as Hank McCoy / Beast[1]
- Oscar Isaac as En Sabah Nur / Apocalypse[2]
- Rose Byrne as Moira MacTaggert[3]
- Tye Sheridan as Scott Summers / Cyclops[4]
- Sophie Turner as Jean Grey:[4] Turner learned archery in preparation for the role.[5]
- Alexandra Shipp as Ororo Munroe / Storm[4]
- Kodi Smit-McPhee as Kurt Wagner / Nightcrawler[6]
- Evan Peters as Peter Maximoff / Quicksilver[7]
- Lucas Till as Alex Summers / Havok[8]
- Ben Hardy as Warren Worthington III / Angel:[9] Hardy practiced indoor skydiving in preparation for his role.[10]
- Lana Condor as Jubilation Lee / Jubilee[11]
- Olivia Munn as Betsy Braddock / Psylocke:[12] Munn practiced swordfighting in preparation for the role.