Tell All Your Friends is the debut studio album by American rock band Taking Back Sunday, released on March 26, 2002 through Victory Records. The group had several lineup changes before settling on vocalist Adam Lazzara, guitarist and vocalist John Nolan, guitarist Eddie Reyes, bassist Shaun Cooper, and drummer Mark O'Connell. Taking Back Sunday released a five-song demo in early 2001, after which, they toured the United States for most of the year. They rented a room in Lindenhurst, New York, where they wrote and demoed songs. In December 2001, the band signed with Victory Records; they began recording their debut album with producer Sal Villanueva at Big Blue Meenie Recording Studio in New Jersey.

In early March 2002, a music video was released for "Great Romances of the 20th Century" and the song was distributed to radio stations. That summer, Taking Back Sunday toured with Brand New and Rufio. In December, a Fight Club-inspired music video was released for "Cute Without the 'E' (Cut from the Team)". The group spent the early part of 2003 touring with The Used and The Blood Brothers before headlining their own tour. After the tour, Nolan and Cooper left the band, and were replaced by Fred Mascherino and Matt Rubano. In September 2003, "You're So Last Summer" was distributed to radio stations and the band began co-headlining a tour with Saves the Day which lasted until November 2003. During the latter month, a music video was released for "You're So Last Summer".

Tell All Your Friends has received mostly positive reviews from critics. It sold 2,000 copies its first week, charting at number 183 on the Billboard 200 chart. The album certified gold in the US, and has sold 790,000 copies as of 2009. It is Victory Records' longest-running release on the Billboard Heatseekers and Independent album charts, charting for 68 weeks on the former and 78 on the latter. In 2012, the band went on tour to celebrate the 10th anniversary of Tell All Your Friends. The band played an acoustic set on the anniversary tour, which was later released in 2013 as the live album TAYF10 Acoustic.