The video sees the band perform the single in the midst of a civil war. Dressed in era-appropriate attire, lead singer Nate Ruess marches on stage while muskets fire around him.
'Some Nights' is the second single from fun.'s sophomore album of the same name.
The music video was directed by Anthony Mandler, who previously worked on Nicki Minaj's 'Starships' and Rihanna's 'California King Bed'.
The band took the stage at Sunday's (June 3) MTV Movie Awards, where they opened the show with their hit song 'We Are Young'.
In May, fun. announced plans to embark on a tour of the UK and Ireland later this year. The band are currently on tour in the US.
> fun.: 'Some Nights' - Album review
Watch Digital Spy's interview with fun. below: