Asked about the song in an interview with The A.V. Club, Brock said that he consciously intended to write something that felt more positive than some of his previous work:
It was a completely conscious thing. I was just kind of fed up with how bad shit had been going, and how dark everything was, with bad news coming from everywhere. Our president George W. Bush is just a fucking daily dose of bad news! Then you've got the well-intentioned scientists telling us that everything is fucked. I just want to feel good for a day.
— Isaac Brock, The A.V. Club
The song was released on February 14, 2004 and was the first Modest Mouse song to gain mainstream popularity. Nearly six months after its release, it became the band's first No. 1 hit on the BillboardModern Rock Tracks chart. It debuted on the Billboard Hot 100 at No. 70 and peaked at No. 14. In Australia, the song was ranked No. 11 on Triple J's Hottest 100 of 2004. In 2013 Triple J created a new list of the Hottest 100 songs of the past 20 years, Float On appeared at No. 45. In July 2009, it was also voted in at No. 94 in Triple J Hottest 100 of All Time. In December 2009 Rolling Stone named it the 39th greatest song of the 2000s (decade). The song is in the key of F# major.