"Phineas and Ferb: Mission Marvel" is a crossover episode of the animated series Phineas and Ferb, featuring characters from Marvel Entertainment. The 22nd broadcast episode of the fourth season and the 196th broadcast episode overall of the series, it aired on August 16, 2013, on Disney Channel and on August 25, 2013, on Disney XD. The episode was released on DVD on October 1, 2013.

Mjolnir, known more formally as Mjölnir is a fictional magical weapon appearing in American comic books published by Marvel Comics. It is depicted as the principal weapon of the superhero Thor. Mjolnir, which first appears in Journey into Mystery #83, was created by writers Stan Lee and Larry Lieber and designed by artists Jack Kirby and Joe Sinnott.