Philip Edward Hartmann was born in Brantford, Ontario, Canada to Rupert and Doris Hartmann; the family was of German Catholic descent.
Hartman's family migrated to the United States in the 1950s, and Hartman attended Westchester High School and Cal State Northridge in Los Angeles, California, becoming a naturalized U.S. citizen in the early-1990s.
The exact timing of his switch from "Hartmann" to "Hartman" is unknown, but all of his acting credits after 1986 were billed under the surname "Hartman".
Hartman and his wife Brynn had two children, Sean Edward Hartman (born 1989) and Birgen Hartman (born 1992).
Looking for what he described as "a psychological release valve", he joined the California-based comedy group The Groundlings in 1975. Hartman met comedian Paul Reubens while working with the group and the two became friends, often writing and working on material together.
One such collaboration was the character of Pee-wee Herman and the script of the feature film Pee-wee's Big Adventure. Hartman also met Jon Lovitz while with The Groundlings.
Hartman worked part time as a graphic artist, including designing album covers for popular rock bands. Hartman's covers include:
Poco's 1978 album Legend (photo)
Firesign Theatre's 1980 album Fighting Clowns (photo)
Three album covers for the band America