Saint Vitus is an American doom metal band formed in Los Angeles in 1978. They are considered to be one of the first doom metal bands, and have been labeled as one of the "big four" of that genre, along with Candlemass, Pentagram and Trouble. Having released nine studio albums to date, Saint Vitus never achieved a popular breakthrough, but have exerted great influence on the development of doom metal, sludge metal, and stoner rock.

The original lineup consisted of Dave Chandler (guitar), Mark Adams (bass), Armando Acosta (drums) and Scott Reagers (vocals). They recorded their first two albums before Scott Weinrich replaced Reagers in 1986. The lineup of Chandler, Adams, Acosta and Weinrich is the longest-lasting. The third album Born Too Late (1986) is generally acknowledged as their best release.

After breaking up in 1996 and briefly reforming in 2003, Saint Vitus reunited again in 2008 with the band's "classic" lineup, featuring Weinrich, Chandler, Adams and Acosta, and embarked on a successful tour. However, after 30 years in the band, Acosta left Saint Vitus in 2009 due to worsening health, and was replaced by Henry Vasquez. By 2016, both Weinrich and Adams had left Saint Vitus and were replaced by Reagers and Pat Bruders respectively, leaving Chandler as the only constant member of the band and reuniting half of the original lineup.