Died in a house fire in the Hollywood Hills, California, just days after "Rowan & Martin's Laugh-In" (1967) actress Teresa Graves perished in a home blaze in Hyde Park, California.
He sidelined frequently into directing, including the Emmy-winning "Gift of Tears." He also directed "Masthead" for the large screen.
His father's family came from Ireland and many of Dennis' character roles contained an Irish brogue.
Logged over 1800 guest roles on TV programs during his four-decade career.
Made his acting debut at age 8 in a children's show production of "H.M.S. Pinafore."
Second wife Barbara Cason appeared as a regular on "It's Garry Shandling's Show." (1986), in which Dennis was brought into one episode as a possible love interest for Barbara.
Though he was only Jason McGuire and Paul Stoddard in the television series "Dark Shadows" (1966) (Sheriff Patterson in the film House of Dark Shadows (1970)), Dennis Patrick was television's first vampire (as Dennis Harrison) in a 1950 episode of "Stage 13" (1950).