Pennywise is an American punk rock band from Hermosa Beach, California, formed in 1988. The band took its name from the antagonist in Stephen King's horror novel It known as Pennywise.

Between their 1991 self-titled debut and 2005's The Fuse, Pennywise released an album every two years on Epitaph Records, a label owned by Bad Religion guitarist Brett Gurewitz. To date, the band has released twelve full-length studio albums, one live album, two EPs and one DVD. Although their first two studio albums were critically acclaimed, Pennywise would not experience worldwide commercial success until the 1995 release of their third studio album, About Time, which peaked at number ninety-six on the Billboard 200, and number fifty-five on Australia's ARIA Charts. The band's mainstream success coincided with a growing interest in punk rock during the 1990s, along with fellow California bands NOFX, Rancid, Blink-182, Bad Religion, Green Day, The Offspring, Lagwagon, and Sublime. By 2007, the band had independently sold over three million records worldwide.

Pennywise's current line-up consists of Jim Lindberg (vocals), Fletcher Dragge (guitars), Randy Bradbury (bass), and Byron McMackin (drums). They had kept their original line-up together until bassist Jason Thirsk died of a self-inflicted gunshot wound in 1996, after which Bradbury joined as his replacement. In August 2009, Lindberg decided to leave the band; he was replaced in February 2010 by Ignite singer Zoli Téglás. With Téglás, the band recorded their tenth studio album, All or Nothing, which was released on May 1, 2012. Lindberg rejoined the band later that year after Téglás was sidelined by a back injury.

The staff of Consequence ranked the band at number 31 on their list of "The 100 Best Pop Punk Bands" in 2019.