"Scotty Doesn't Know" is a song written and performed by the American rock band Lustra. Originally written for the 2004 film EuroTrip, the song contains numerous lewd references to how Scotty's girlfriend Fiona has been cheating on him for an extended period of time; the song is written from the perspective of the person she is having the affair with. The song was eventually released on their 2006 album Left for Dead. The song peaked at #53 on the U.S. Billboard Pop chart, #39 on the Digital Songs chart and at #75 on the Hot 100, mainly due to the high amount of digital downloads.