Maceo Parker was born in Kinston, North Carolina, on February 14, 1943. His parents sang in their church choir, but the stronger pull came from an uncle who led a local jazz and R&B band called the Blue Notes. Maceo took up the saxophone, his brother Melvin the drums and his brother Kellis the trombone, and the uncle put the three of them on between the band's sets as the Junior Blue Notes. The brothers were seasoned players by the time they enrolled at North Carolina A&T, where they studied music.

In 1963 Melvin graduated and won an audition as James Brown's new drummer. When he asked whether Brown could use a saxophonist as well, Maceo was offered a place in the band too. He began on baritone and moved to tenor, and his short, rhythmic, staccato lines suited Brown's tightening sound exactly. After a solo on Brown's 1965 hit "Papa's Got a Brand New Bag," he became one of the key players in the recording and touring band, and his horn is on "I Got You (I Feel Good)," "Mother Popcorn," "Sex Machine" and "Cold Sweat." Brown's habit of shouting for him on record, "Maceo! Blow your horn!", made him the most famous sideman in funk. He is also credited on tenor saxophone on Soul on Top (King, 1970), Brown's big-band album with the Louie Bellson Orchestra, arranged and conducted by Oliver Nelson, with Ray Brown on bass.

In March 1970 Parker, Melvin and several other members of Brown's band quit and formed Maceo & All the King's Men, which toured for two years and made Doing Their Own Thing (1970) and Funky Music Machine (1972). In January 1973 he rejoined Brown, and in the same year Maceo & the Macks put "Parrty (Part I)" at No. 71 on the pop singles chart. His jazz-label work from the period includes tenor saxophone on Esther Phillips's Alone Again, Naturally (Kudu, 1972), with Hank Crawford, George Benson, Ron Carter and Billy Cobham in the credits, and a tenor solo on the title track of the organist Johnny Hammond's The Prophet (Kudu, 1973). Both were Creed Taylor productions arranged and conducted by Pee Wee Ellis, and The Prophet also credits Eric Gale, Pepper Adams and Cecil Payne. His own album Us followed in 1974. In 1975 he left again, with trombonist Fred Wesley and other Brown alumni, for George Clinton's Parliament-Funkadelic, where he appeared on Parliament's Mothership Connection (1975) and on Bootsy Collins's Rubber Band records. Wesley and Parker also recorded as Fred Wesley and the Horny Horns, on A Blow for Me, a Toot to You (1977) and Say Blow by Blow Backwards (1979). Parker returned to Brown from 1984 to 1988 and, in the same years, played on the Red Hot Chili Peppers' Freaky Styley (1985) and Keith Richards's Talk Is Cheap (1988).

His solo career began in 1990 with Roots Revisited, which carries more jazz than the funk reputation suggests. Recorded with Wesley on trombone, Pee Wee Ellis on tenor, Don Pullen on organ, Rodney Jones on guitar and Bill Stewart on drums, with Bootsy Collins on the closing track, it covers Ray Charles ("Them That Got"), Charles Mingus ("Better Get Hit in Yo' Soul"), Curtis Mayfield, Harold Arlen and a Jay McShann blues credited to McShann, Charlie Parker and Walter Brown. It spent ten weeks at the top of Billboard's contemporary jazz chart, and AllMusic's Scott Yanow heard a throwback to 1960s soul-jazz and a player who could hold his own on a bebop date. Mo' Roots (1991) added Larry Goldings on Hammond organ and took in Horace Silver's "Sister Sadie" and "Hamp's Boogie Woogie," a nod to Lionel Hampton; it reached No. 4 on Billboard's traditional jazz albums chart. Goldings returned the favor on his own Whatever It Takes (Warner Bros., 1995), where Parker plays alto on three tracks beside David Sanborn, Joshua Redman, Peter Bernstein and Bill Stewart.

The live album Life on Planet Groove, recorded at the Stadtgarten club in Cologne and released in 1992, pushed the funk forward again and reached No. 3 on Billboard's jazz albums chart. It was his first recording with the Dutch alto saxophonist Candy Dulfer, and its band of Wesley, Ellis, Goldings, Jones and Kenwood Dennard became the template for the albums that followed: Southern Exposure (1993), made with New Orleans players including the bassist George Porter Jr., the guitarist Leo Nocentelli, the drummer Herman Ernest III and the trumpeter Kermit Ruffins; Funk Overload (1998, with his son Corey rapping on three tracks); Dial: M-A-C-E-O (2000, which sets his own tunes beside songs by Prince and by Paul and Linda McCartney, with Prince as a featured guest); Made by Maceo (2003); and School's In! (2005).

Outside his own records, he guested on De La Soul's Buhloone Mindstate (1993), toured as the opening act for the Dave Matthews Band in 1998 and sat in on their December 19, 1998 Chicago show, later released as a live album, and from 1999 became a regular on Prince's studio records and bandstand. He toured with Prince's band in 2004, played in the 21-night run at London's O2 arena in 2007 and the 21-night run at the Los Angeles Forum in 2011.

His most jazz-facing project of the 2000s was Roots & Grooves, built from European concerts with Germany's WDR Big Band as a tribute to Ray Charles, one of his most important influences; it won a Jammie for best jazz album in 2009. He returned to the WDR band for Soul Classics (2012) and, with the arranger and conductor Michael Abene, for It's All About Love (2018), the same year he re-recorded his best-known live album as Life on Planet Groove - Revisited. His most recent studio album, Soul Food: Cooking with Maceo, appeared in 2020. He was inducted into the North Carolina Music Hall of Fame in October 2011, received a lifetime achievement award from the Victoires du Jazz in Paris in July 2012 and the North Carolina Heritage Award in May 2016. His autobiography, 98% Funky Stuff: My Life in Music, was published by Chicago Review Press in February 2013, and Craig Robinson played him in the 2014 James Brown film Get on Up. He has also toured with the Ray Charles Orchestra and the Raelettes in a Charles tribute, including the Monterey Jazz Festival in 2016 and the Playboy Jazz Festival in 2019.

Parker is a funk and soul-jazz saxophonist, and both words are earned. His reputation rests on James Brown's records, Parliament-Funkadelic and Prince's bands, where he typically supplies short, tightly articulated solos that lock into the rhythm section. AllMusic files him under R&B and jazz, in the styles of funk, soul and soul jazz, and describes his Brown-era tenor playing as rich, rhythmic and full of sharp, staccato lines. He plays a gold-plated Selmer Mark VI alto. His own albums are a mixture rather than a pivot: the funk catalog of Life on Planet Groove and Funk Overload sits beside Roots Revisited and Mo' Roots, which draw on Mingus, Silver, Hampton and a blues credited to Jay McShann and Charlie Parker, and which put him on Billboard's jazz charts, and beside the big-band Ray Charles records with the WDR Big Band.

The jazz side is documented rather than claimed. He studied music at North Carolina A&T, came up in his uncle's jazz and R&B band, played the Ray Charles tribute at jazz festivals worldwide, and records with jazz organists and drummers, among them Don Pullen, Larry Goldings and Bill Stewart. His lineage runs through Ray Charles and the Creed Taylor Kudu sessions he played on, and AllMusic's list of related artists includes Stanley Turrentine, Hank Crawford and Gene Ammons. In the other direction, Steve Coleman first listened to R&B and funk bands built around saxophonists like Parker before Chicago's tenor tradition pulled him toward jazz.