"What a Catch, Donnie" is Fall Out Boy's second digital download single and third radio single from their fourth studio album Folie à Deux (2008). It was first released as part of the buildup to the new album on iTunes on October 14, 2008, and charted on the US and Canadian singles charts. The track features numerous musicians performing cameo appearances in the song, singing lines from past Fall Out Boy songs. Bassist and lyricist Pete Wentz has said that he wrote the song to remind himself of vocalist and guitarist Patrick Stump. Fall Out Boy played the song live on Late Night with Jimmy Fallon.

Folie à Deux is the fourth studio album by American rock band Fall Out Boy, released on December 10, 2008, by Island Records. As with their previous two albums From Under the Cork Tree (2005) and Infinity on High (2007), its music was composed by lead vocalist and guitarist Patrick Stump, with lyrics penned by bassist Pete Wentz. Regarding the writing process, the band considered Folie à Deux to be their most collaborative record.