“X-Men: First Class” is the fifth installment in the X-Men film series. Released in 2011, it follows the earlier films X-Men (2000), X2 (2003), X-Men: The Last Stand (2006), and the spin-off X-Men Origins: Wolverine (2009). That makes it the fifth X-Men movie overall.
The film is also a prequel and soft reboot, taking place mainly in 1962. It introduces younger versions of Charles Xavier, who becomes Professor X, and Erik Lehnsherr, who becomes Magneto. James McAvoy and Michael Fassbender play the characters before their ideological split.
A common mix-up comes from counting only the mainline films. By that narrower method, First Class is the fourth mainline X-Men movie, after the original trilogy. However, when the Wolverine spin-off is included in the broader film series, it is correctly described as the fifth installment. Its follow-up, X-Men: Days of Future Past (2014), connects the prequel cast with the original trilogy’s characters.