Ugonna Okegwo was born March 15, 1962, in London, England, to a German mother and a Nigerian father, and was raised in Germany. He grew up listening to James Brown, Jimi Hendrix, Miles Davis, and Ornette Coleman before discovering Charles Mingus, and he has said the walking bass lines and ostinato figures he heard first in funk and rock and roll were what drew him to the instrument. He began on electric bass and switched to upright at 21 after taking a violin-making class.

In 1986 Okegwo moved to Berlin to study with two American expatriates, bassist Jay Oliver and pianist Walter Norris. There he caught the attention of trombonist Lou Blackburn, a Mingus alumnus, who invited him to tour Europe with his Afro-jazz group Mombasa. Through that group Okegwo met and played with trumpeter Joe Newman, drummer Oliver Jackson, and bassist Major Holley, who encouraged him to relocate to New York.

He made the move to Manhattan in 1989 and began working with saxophonists Big Nick Nicholas, Junior Cook, and James Spaulding. A 1992 call from vocalist Jon Hendricks led to steady sideman work on stage and in the studio, documented on Hendricks's live album Boppin' at the Blue Note, and in 1994 Hendricks brought Okegwo to the White House to perform for the President. That same year Okegwo earned a Bachelor of Fine Arts from Long Island University, graduating summa cum laude. In the early 1990s his playing also drew the interest of pianist Jacky Terrasson and drummer Leon Parker, and the three formed a trio that built one of the decade's most talked-about young rhythm sections at clubs including the Village Gate and Bradley's, going on to record together across a run of Blue Note albums: Jacky Terrasson (1994), Reach (1995), the live Alive (1998), What It Is (1999), and A Paris... (2000).

Around 1997 and 1998 Okegwo began working with trumpeter Tom Harrell, a relationship that became the longest and most consistent association of his career. He appears on Harrell's The Art of Rhythm (1998), Paradise (2001), the live Live at the Village Vanguard (2002), Wise Children (2003), Light On (2007), Prana Dance (2009), Number Five (2012), Roman Nights (2010), The Time of the Sun (2011), Colors of a Dream (2013), Trip (2014), First Impressions (2015), Something Gold Something Blue (2016), Moving Picture (2017), Oak Tree (2022), and Alternate Summer (2024), a nearly three-decade run covering essentially the entire discography of Harrell's working quintets of that era. Harrell has singled him out publicly, saying "Ugonna does some really creative things that I haven't heard anyone do with his articulation and timing."

Alongside that steady sideman work, Okegwo built a smaller catalog of leader and co-led dates. He was one of four equally billed musicians, alongside saxophonist Donny McCaslin, pianist Bruce Barth, and drummer Billy Drummond, on Exile and Discovery (1998, Naxos Jazz), sometimes described as McCaslin's own leader debut but credited on Discogs and on the sleeve to all four musicians. He co-led a trio session with Bruce Barth and drummer Al Foster on Live at the Village Vanguard (2002, MAXJAZZ), and released his own leader debut, UOniverse, recorded in 2002 and issued in 2004 on Satchmo Jazz Records, a quartet date with drummer Donald Edwards, pianist Xavier Davis, and saxophonist Sam Newsome mixing his own compositions with reworked standards. Two decades later he formed an organ-trio partnership with guitarist Oz Noy and drummer Ray Marchica, documenting a series of pandemic-era outdoor jams in Manhattan's Riverside Park on Riverside (2022, Outside In Music). In 2023 he appeared as one of four equally billed musicians, with guitarist Roni Ben-Hur, trumpeter Ingrid Jensen, and drummer Jason Tiemann, on Love Letters (Mighty Quinn Records), a session that Discogs credits jointly to all four players rather than to Ben-Hur alone.

Okegwo remains active on New York's mainstream jazz scene, continuing to record and tour with Harrell's ensembles into the 2020s and appearing on recent sideman dates including Wayne Escoffery's Like Minds (2023), Steve Slagle's Nascentia (2021), Aaron Seeber's First Move (2022), and Jason Forsythe's It's About Time (2025). He has also worked with the Mingus Big Band and is listed on the faculty of Columbia University's Department of Music.

Okegwo's playing fuses the walking-bass language of mainstream jazz with the ostinato feel of the funk and rock he grew up on, giving his lines a distinctive rhythmic drive that critics and collaborators alike have singled out. He has spent his career moving between tightly interactive small-group settings, the long-running Tom Harrell quintet chief among them, and looser, groove-based contexts such as his organ trio with guitarist Oz Noy, without losing the individuality of his articulation and timing that Harrell has praised directly. His sound places him within the broad, still-active New York mainstream and post-bop scene built around working bands rather than one-off studio dates.