Lawrence Joseph Mullen Jr., the middle child and only son of Lawrence Joseph Mullen Sr. and Maureen (née Boyd) Mullen, was born on 31 October 1961 in Artane, Dublin, Ireland, and lived there, on Rosemount Avenue, until his twenties. His father was a civil servant and his mother a homemaker. He has an elder sister, Cecilia, and had a younger sister, Mary, who died in 1973. He attended the School of Music in Chatham Row to learn piano at the age of eight and then began drumming in 1971 at the age of 9, under the instruction of Irish drummer Joe Bonnie. After Bonnie’s death, his daughter Monica took over for him, but Mullen gave up the lessons and started playing by himself. His mother died in a car accident in 1976.

Mullen used the money he had saved and with his father’s help bought a drum kit, made by a Japanese toy company, which his sister Cecilia’s friend was selling. He set up the kit in his bedroom and his parents allotted him certain times to practice. His father then got him into the Post Office Workers Band, which played orchestral melodies with percussion, along with marching band standards. Mullen spent approximately two years in the Post Office Workers Band, overlapping with his time in U2. He attended Scoil Colmcille, Marlborough Street, Dublin. He took the exams for Chanel College and St. Paul’s, two Catholic schools his father wanted his son to attend. After the accidental death of Larry’s younger sister in 1973, his father gave up the idea of pushing his son into those schools and sent Larry to Mount Temple Comprehensive School, the first interdenominational school in Ireland.

Mullen’s father suggested that he place a notice on the Mount Temple bulletin board, saying something to the effect of “drummer seeks musicians to form band.” U2 was founded on 25 September 1976 in Mullen’s kitchen in Artane. Attending the first meeting were Mullen, Paul “Bono” Hewson, David “The Edge” Evans and his brother Dik, Adam Clayton, and Mullen’s friends Ivan McCormick and Peter Martin. Mullen later described it as “‘The Larry Mullen Band’ for about ten minutes, then Bono walked in and blew any chance I had of being in charge.” McCormick and Martin soon left, and the group settled on the name “Feedback” because it was one of the few technical terms they knew. The band later changed their name to “The Hype”, and again to “U2” for a 1978 talent contest in Limerick, Ireland, that they entered and won as a four-piece. Days after the competition, the band’s reduction to a four-piece lineup became permanent after they parted ways with Dik.

Mullen left school in 1978, having taken his Intermediate Certificate exams. The school offered him the chance to complete his Leaving Certificate exams. He and his sister Cecilia worked for an American company in Dublin, involved in oil exploration off the coast of Ireland. Mullen worked there for a year in the purchasing department, with the prospect of becoming a computer programmer in their geology section.

Mullen’s drumming style is influenced by his experience in marching bands during his adolescence, which helped contribute to the militaristic beats of songs such as “Sunday Bloody Sunday”. Author Bill Flanagan said that he plays “with a martial rigidity but uses his kit in a way a properly trained drummer would not”; he tends to transition from the snare drum onto tom-toms positioned on either side of him, contrasting with how they are traditionally used. Mullen occasionally rides a tom-tom the way other drummers would play a cymbal, or rides the hi-hat how others would play a snare. He admitted his bass drum technique is not a strength, as he mostly played the snare in marching bands and did not learn to properly combine the separate elements together on a full kit. As a result, he uses a floor tom to his left to create the effect of a bass drum, an arrangement he began to use while recording “Pride (In the Name of Love)” in 1984 at the influence of producer Daniel Lanois. He said, “I couldn’t do what most people would consider a normal beat for the song, so I chose alternatives.” Flanagan said that his playing style perfectly reflects his personality: “Larry is right on top of the beat, a bit ahead—as you’d expect from a man who’s so ordered and punctual in his life.

Mullen has worked on many musical projects outside of U2 in his career, including collaborations with Maria McKee. Mullen contributed to U2 producer Daniel Lanois’s 1989 album Acadie. In 1990, Mullen co-wrote and arranged an official Irish national football team song “Put ‘Em Under Pressure” for the FIFA World Cup. He and Clayton collaborated with Mike Mills and Michael Stipe from R.E.M. to form the one-performance group Automatic Baby, solely for the purpose of performing “One” for MTV’s 1993 inauguration ball for US President Bill Clinton; the group’s name refers to the titles of both latest bands’ albums at the time, Achtung Baby and Automatic for the People. For Nanci Griffith’s 1994 album Flyer, he and Clayton performed in the rhythm section on several songs, while Mullen also mixed three songs. Mullen played drums on many of the songs on Emmylou Harris’ 1995 album Wrecking Ball.

Mullen met his partner, Ann Acheson, in their first year at Mount Temple Comprehensive School. The two have been together for over 40 years and they have three children. He is a first cousin of Irish actor Conor Mullen. As U2 became increasingly successful, Larry Mullen had to add the suffix “Junior” to his surname to avoid confusion with his father, who was receiving large tax bills meant for his son. In 1995, Mullen had surgery on his back because he had been carrying an injury since The Joshua Tree tour. He and Clayton own houses near Bono and The Edge in Southern France to make it easier to record with U2 in the south of France.

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 relented, allowing The Edge to continue using drum machines, which contributed heavily to the album’s electronic feel.

Mullen and Clayton contributed to the soundtrack to the 1996 movie Mission: Impossible, which included recording the theme song, whose time signature was changed from the original 4 time signature to an easier and more danceable 4 time signature. The “Theme from Mission: Impossible” reached number 8 on the U.S. Billboard Hot 100, and was nominated for the Grammy Award for Best Pop Instrumental Performance (Orchestra, Group or Soloist) in 1997.

Mullen and U2 have won more than 60 awards, including 22 Grammy Awards. At the Grammy Awards, the band has won Best Rock Duo or Group with Vocal seven times, Album of the Year twice, Record of the Year twice, Song of the Year twice, and Best Rock Album twice. In March 2005, Mullen was inducted into the Rock and Roll Hall of Fame as a member of U2, in their first year of eligibility. In 2016, Rolling Stone ranked Mullen the 96th-greatest drummer of all time. He was placed at number 21 on Stylus Magazine’s list of the 50 Greatest Rock Drummers.

Mullen’s film debut was in a film by Phil Joanou called Entropy where he played himself alongside bandmate Bono. He played a thief in Man on the Train, which starred Donald Sutherland. Filmed in Orangeville, Ontario, Canada, Man on the Train was released in 2011. The following year, it was announced that Mullen would appear in his second film, A Thousand Times Goodnight, starring Juliette Binoche. On 3 September 2013 the film won Special Grand Prix of the Jury at Montreal World Film Festival.

Mullen performed on Underworld’s song “Boy, Boy, Boy” from their 2007 album, Oblivion with Bells. Ten years later he appeared on Alice Cooper’s 2017 album Paranormal.

In July 2020, Mullen was invited to join the Academy of Motion Pictures Arts and Sciences.