Lawrence Joseph "Larry" Mullen, Jr. is the drummer for the Irish rock band U2. He is the founder of U2, which was originally known as "The Larry Mullen Band" at its inception. His drumming skills are notable on songs such as "Sunday Bloody Sunday" and "Bullet the Blue Sky." He has worked on numerous side projects during his career, including a collaboration with Michael Stipe and Mike Mills of R.E.M. to form Automatic Baby in 1993 and working with bandmate Adam Clayton on the re-recording of the theme to Mission: Impossible, in 1996. He and U2 have won several awards, including 22 Grammy awards

Mullen, the middle child and only son of Larry and Maureen Mullen, was born 31 October 1961, and raised in Artane, on the north side of Dublin, Ireland. Mullen began drumming in 1970, at the age of 9 under the instruction of Irish drummer Joe Bonnie and later, Bonnie's daughter Monica. In 1971, Mullen was introduced to one of his father's long time friend's and drummer, Wesley Kerr who instructed him up until the death of his younger sister, Mary, in 1973. His mother died in a car accident in November 1978, two years after U2 was founded.

Before founding U2, Mullen was involved in a Dublin marching band called the Artane Boys Band, contributing to the martial beats common in Mullen's work, such as the song "Sunday Bloody Sunday". Mullen founded U2 in the fall of 1976 by placing a famous notice on the Mount Temple Comprehensive School bulletin board, saying something to the effect of "drummer seeks musicians to form band." The band, originally consisting of Mullen, Paul "Bono" Hewson, David "The Edge" Evans, his brother Dick Evans, Adam Clayton, and Mullen's friends Ivan McCormick and Peter Martin, was originally known as the "Larry Mullen Band", but the name quickly changed to "Feedback", as that was one of the few musical terms they knew, and subsequently "The Hype". Soon after the band formed, McCormick and Martin left, and the band, by then known as The Hype was a 5-piece. Just before they won a Limerick, Ireland talent contest, they changed their name again, for the final time, to U2, formally done at a farewell concert for Dick Evans, becoming the 4-piece band they are today.

As U2 grew more popular, Mullen added the "Junior" suffix to his name to stop confusion with his father (also Larry Mullen), who was receiving large tax bills meant for his son. Mullen is unmarried, but has lived with his girlfriend Ann Acheson for more than 20 years. They have three children, Aaron Elvis (born 1995), Ava (born 1998), and Ezra (born 2001).

He is known to be the "brakes of the band", and prefers to let the other band members take the spotlight at interviews. Mullen has also played synthesizer or keyboards on several songs, including "United Colours" from 1995's Original Soundtracks 1, an album that Mullen has always disliked. Mullen loves Harley Davidson motorcycles and is a big fan of Elvis Presley. He currently lives in the Howth suburb of Dublin.

After forming U2, Mullen's drumming style and techniques began to evolve. In the early days of the band, his contributions to the band was often limited to fills and drum rolls, but he became more involved in the writing of the songs later, particularly in conjunction with Adam Clayton, his partner in the rhythm section, with whom he has collaborated on solo projects. When the band was first being signed to CBS Records, they refused to sign the band unless Mullen was fired.] He was not, and as a result, his drumming became more integrated into the song structures. Mullen's experience as a teenager in the Artane Boys Band heavily contributed to the martial beat featured in many of U2's songs, helping to evoke military imagery.

During the recording of the album Pop in 1996, Mullen suffered from severe back problems. Recording was delayed due to surgery. When he left the hospital, he arrived back in the studio to find the rest of the band experimenting more than ever with electronic drum machines, something driven largely by The Edge's interest in dance and hip-hop music, and, given his weakness after the operation, he finally gave in to The Edge and continued to use drum machines, which contributed heavily to the album's electronic feel.

Mullen has had tendinitis problems throughout his career. As a means to reduce inflammation and pain, he began to use specially designed Pro-Mark drumsticks. He uses Yamaha drums and Paiste cymbals. He was placed at 21 in Stylus Magazine's list of the 50 Greatest Rock Drummers.

Mullen has worked on many solo projects in his career, including collaborations with Maria McKee, Nancy Griffith, and U2 producer Daniel Lanois. Mullen played drums on many of the songs on the 1995 Emmylou Harris album Wrecking Ball. Mullen, along with bandmate Adam Clayton, recorded the soundtrack to the 1996 movie remake of Mission: Impossible, including the theme song, whose time signature was changed from the original 5/4 time signature to an easier and more danceable 4/4 time signature. The "Theme from Mission: Impossible" reached 8 on the U.S. Billboard chart, and was nominated for a Grammy award in the "Best Pop Instrumental Performance" category. Mullen worked with producer Daniel Lanois on his album Acadie..