"I Write Sins Not Tragedies" is a song by American rock band Panic! at the Disco. It is the second single from their debut studio album, A Fever You Can't Sweat Out (2005), and was released in the United States as a digital download on January 16, 2006.
The song is built upon a pizzicato cello motif that was played by session musician Heather Stebbins. It reached a peak of No. 7 on the US Billboard Hot 100, the band's only top-40 hit until the release of "Hallelujah" in 2015, and only top-10 hit until "High Hopes" in 2018.
While the song failed to reach the top 10 of the Modern Rock Tracks chart, peaking at No. 12, the song's success on the Hot 100 and Mainstream Top 40 (at No. 2) made the song one of the biggest modern rock hits of 2006, and it is still one of the band's most-played songs on alternative radio stations.