Hakim was born in New York City on February 12, 1959. His father, Hasaan Hakim, was a trombonist. Omar started playing the drums at the age of five, and first performed in his father’s band four or five years later.

Hakim first came to major attention backing Carly Simon in 1980, and joined Weather Report in 1982. He played drums on David Bowie’s 1983 album Let’s Dance, as well as the follow-up, Tonight, in 1984. Bowie described Hakim as “a fascinating drummer, with impeccable timing” and “always fresh in his approach”.

Between 1988 and 1989 Hakim appeared regularly as the house band drummer in The Sunday Night Band during the first half season of the acclaimed music performance program Sunday Night on NBC late-night television. After being temporarily replaced by drummer J. T. Lewis for the remainder of that season, Hakim reappeared in the band for the second season in the fall of 1989, when the program returned under the new name Night Music.

“By this time, Hakim was teaching himself to program drum machines, which put him in even greater demand as a pop, rock, and R&B session musician, and landed him work with Madonna.” He kept working in jazz fusion, playing with Roy Ayers, George Benson, Miles Davis, Lee Ritenour, Joe Sample, David Sanborn, and John Scofield across the 1980s and 1990s. His debut album as leader, Rhythm Deep, was released in 1989, also featured his singing, and was nominated for a Grammy Award.

In the 1990s, Hakim developed further in electronic percussion, which gave him more opportunities as a session musician: he recorded with pop stars Mariah Carey, Celine Dion, and Jewel. His jazz career had faded by the mid-1990s. His second album as leader, The Groovesmith, was released in 2000.

Hakim was featured on the cover of Modern Drummer Magazine in 2014, and was on the cover of DrumHead Magazine in 2017.

On June 18, 2015, Journey announced that Hakim would replace longtime drummer Deen Castronovo on their North American tour after Castronovo was arrested for domestic violence in Salem, Oregon.

Hakim became the Chairman of the Percussion Department of Berklee College of Music in 2017, replacing the previous Department Chair, John Ramsey.