Humphrey began playing drums at age 8, taking private lessons in Detroit. In high school he played baritone horn, trombone and drums in the school band. Upon graduation he entered the U.S. Navy and studied under Kenneth J. Abendschein, touring the world and playing with many jazz figures of 1950s.
After discharge from the service, he worked as a session drummer in New York for jazz artists such as Wes Montgomery, John Coltrane, Les McCann, Kai Winding, Jimmy Smith, Charles Mingus, Joe Williams, Lee Konitz, Blue Mitchell, Gene Ammons and the Harry James Band (replacing Buddy Rich). He later moved to Los Angeles and joined the Harry "Sweets" Edison group with Tommy Flanagan and Frank Delarossa. He recorded with Larry Williams and Johnny "Guitar" Watson and toured and recorded with Marvin Gaye, The Four Tops, The Supremes, Tony Orlando, Jerry Garcia, Burt Bacharach, Diahann Carroll, Sammy Davis, Jr. and Bill Medley.
As a bandleader, he recorded under the name Paul Humphrey and the Cool Aid Chemists, with keyboardist Clarence MacDonald, guitarist David T. Walker, and bassist Bill Upchurch. In 1971, this ensemble had two hits, "Cool Aid" (US #29, US R&B Singles #14) and "Funky L.A." (US R&B Singles #45). He also recorded an album as head of the Paul Humphrey Sextet in 1981.
Humphrey was one of the drummers on Marvin Gaye's album Let's Get It On. He also recorded with Steely Dan, Frank Zappa, Jimmy Smith, Al Kooper, Jackie DeShannon, Natalie Cole, Albert King, Quincy Jones, Dusty Springfield, Jean-Luc Ponty, Michael Franks, Maria Muldaur, Marc Bolan and many others.
Humphrey was the featured drummer for both the Lawrence Welk orchestra and television show from 1976 to 1982. He and his wife Joan are the parents of two children, Pier and Damien, who appeared with their father on the Welk show's annual Christmas episode.
- Paul Humphrey and the Cool Aid Chemists (Lizard Records, 1971) No. 170, R&B Albums No. 31
- "Detroit" b/w "Cool Aid" (Lizard Records, 1971) 45 rpm, (US #29, US R&B Singles #14)
- "Funky L.A." b/w "Baby Rice" (Lizard Records, 1971) 45 rpm (US R&B Singles #45)
- Supermellow (Blue Thumb, 1972)
- "Supermellow" b/w "Poppa Charlie and Chip" (Blue Thumb, 1973) 45 rpm
- America, Wake Up (Blue Thumb, 1973)
- "Cochise" b/w "What's That Noise P.K.?" (Blue Thumb, 1974) 45 rpm
- The Drum Session (Philips Records, 1975) with Louis Bellson, Shelly Manne & Willie Bobo
- "Humphrey's Overture" b/w "Bionic Salsa" (Happy Fox Records, 1977) 45 rpm
- Me And My Drums (Stanson Records, 1979)
- "Scream & Shout" b/w "Here To Stay" (Stanson Records, 1979) 45 rpm
- "One Out Of Six" b/w "Me And My Drums" (Stanson Records, 1980) 45 rpm
As sideman (partial list)
With Steely Dan
- Aja (ABC, 1977)
With Monty Alexander
- Alexander the Great (Pacific Jazz, 1964)
With Mel Brown
With Kenny Burrell
- 'Round Midnight (Fantasy, 1972)
With Joe Cocker
With Jerry Garcia
- Pure Jerry: Keystone Berkeley, September 1, 1974 (Jerry Made, 2004)
With Marvin Gaye
- Welcome Home (World Pacific, 1968)
With Stan Kenton
- Hair (Capitol, 1969)
With Charles Kynard
- Reelin' with the Feelin' (Prestige, 1969)
- Woga (Mainstream, 1972)
- Your Mama Don't Dance (Mainstream, 1973)
With Les McCann
- The Gospel Truth (Pacific Jazz, 1963)
- Soul Hits (Pacific Jazz, 1963)
- Spanish Onions (Pacific Jazz, 1964)
- McCanna (Pacific Jazz, 1964)
- A Bag of Gold (Pacific Jazz, 1963-64 )
- McCann/Wilson (Pacific Jazz, 1964) with the Gerald Wilson Orchestra
- But Not Really (Limelight, 1965)
- Beaux J. Pooboo (Limelight, 1965)
- Live at Shelly's Manne-Hole (Limelight, 1966)
- Live at Bohemian Caverns - Washington, DC (Limelight, 1967)
- Another Beginning (Atlantic, 1974)
With Merl Saunders
- You Can Leave Your Hat On (Fantasy, 1976)
With Jimmy Smith
- Root Down (Verve, 1972)
With Gerald Wilson
With Frank Zappa
With Gene Harris
- A Little Piece of Heaven (Concord, 1993)
- Funky Gene's (Concord, 1994)
- It's The Real Soul (Concord, 1995)
- Brotherhood (Concord, 1995)
- In His Hands (Concord, 1997)
- Down Home Blues (Concord, 1997)
- Paul Humphrey Sextet liner notes
- Ron Wynn (1935-10-10). "Paul Humphrey | Biography". AllMusic. Retrieved 2014-05-28.
- Paul Humphrey & the Cool Aid Chemists Billboard Singles, Allmusic.com
- Paul Humphrey Billboard Singles, Allmusic.com
- "Let's Get It On - Marvin Gaye | Credits". AllMusic. Retrieved 2014-05-28.
- "The Drummers of Steely Dan". Granatino.com. 1998-08-25. Archived from the original on 2013-09-27. Retrieved 2014-05-28.
- "paul humphrey". United-mutations.com. 1935-10-10. Retrieved 2014-05-28.
- Billboard, Allmusic.com
- "Paul Humphrey and His Cool Aid Chemists – Detroit". Flea Market Funk. 2008-02-13. Retrieved 2014-05-28.