"Lying Is the Most Fun a Girl Can Have Without Taking Her Clothes Off" is the fourth single by rock band Panic at the Disco, from the album A Fever You Can't Sweat Out. Released on August 7, 2006, it is the fourth single overall, but third commercial single ("The Only Difference Between Martyrdom and Suicide Is Press Coverage" was not commercially released as a single). The song is sometimes referred to by the shortened title "Lying Is the Most Fun" for radio.

The song's title originates from a line in the 1997 play "Closer", written by Patrick Marber. The line was originally spoken by the character Alice who, in the debut performance, was portrayed by English actress Liza Walker. It was also repeated in the 2004 film of the same name, spoken by the same elusive character Alice, this time portrayed by Natalie Portman. The prior Panic! at the Disco single "But It's Better If You Do" takes its name from the line after "Lying Is the Most Fun a Girl Can Have Without Taking Her Clothes Off" in both the play and the film.