Jon Theodore is an American drummer best known as the current drummer for Queens of the Stone Age, and as a former member of The Mars Volta. Theodore is also a member of One Day as a Lion.

Known for his explosive, multi-textural playing style, Theodore was a member of both Golden and Royal Trux before joining The Mars Volta in 2001. Theodore remained within the band for five years, recording the band's first three studio albums, De-Loused in the Comatorium (2003), Frances the Mute (2005) and Amputechture (2006), before departing at the request of guitarist and bandleader Omar Rodríguez-López.

Theodore subsequently formed a collaboration with Rage Against the Machine vocalist Zack de la Rocha, entitled One Day as a Lion, and performed on Incubus frontman Brandon Boyd's solo album, The Wild Trapeze (2010). In 2012, Theodore replaced his Mars Volta successor Thomas Pridgen in the supergroup Giraffe Tongue Orchestra, though by 2015 the lineup had reverted to Pridgen on drums.

In 2013, Theodore joined Queens of the Stone Age, replacing Joey Castillo, who left the band citing burnout from constant touring. Although Dave Grohl recorded the drums on Queens of the Stone Age's sixth studio album ...Like Clockwork (2013), Theodore accompanied them on the subsequent tour and has since become a full-time member.

Theodore first started playing drums at the age of 15. He was soon involved with his high school concert band at Gilman School in Baltimore, Maryland, and took lessons on a full kit shortly after. It was at this point that he studied percussion and learned how to map arrangements; dedicated practice had already become a habit. He also listened to a great variety of music, growing to love the likes of Billy Cobham, Elvin Jones and John Bonham. He studied at the Oberlin Conservatory of Music in Ohio.

Around the end of his time in high school, he joined the band Golden and recorded and toured with them for ten years. He also played with Royal Trux for a year and a half. It was during this time that he met Cedric Bixler Zavala and Omar Rodríguez-López, who were performing their first gig with their experimental dub band De Facto in El Paso, TX. They became friends and the former At the Drive-In duo would later invite Theodore to join their Latin-tinged prog-rock band, The Mars Volta. Theodore was The Mars Volta's drummer from 2001 to 2006. 

Theodore has also completed a collaboration with Zack de la Rocha of Rage Against the Machine entitled One Day as a Lion. Their first EP was released on July 22 of 2008. In January 2012, he joined Giraffe Tongue Orchestra, replacing fellow former Mars Volta drummer Thomas Pridgen.  He recently played as Dam Funk's touring drummer during his Fall 2012 US Tour.

A press release from the band Queens of the Stone Age revealed that Theodore would contribute drums on their upcoming album ...Like Clockwork. He played on the title track on the album, which was the first Queens album to reach number one on the Billboard 200. It also reached number two on the UK Albums Chart and was nominated for three Grammy Awards, including Best Rock Album. Following the release of the album in 2013, he became the permanent drummer of Queens of the Stone Age.

In 2018, Theodore performed drums on certain sections of the score for the video game Red Dead Redemption 2. His Queens of the Stone Age bandmates Josh Homme and Michael Shuman also are featured on the score.