Pankow was born in St.Louis,Missouri,the son of Marion,a homemaker,and Wayne Pankow,who worked in magazine advertising sales.He is the younger brother of trombonist James Pankow,a founding member of the legendary rock group Chicago.He is from a Catholic family of German and Irish descent.Pankow grew up in Park Ridge,Illinois,and attended Maine South High School and later,Northeastern Illinois University.
Pankow,a veteran actor of stage,film and television,appeared for seven seasons as Ira Buchman on the NBC sitcom Mad About You.Pankow is a series regular on the Showtime/BBC series Episodes playing American television executive Merc Lapidus.He played federal agent John Vukovich opposite William Petersen and Willem Dafoe in To Live and Die in L A.
Pankow has been married to actress Kristine Sutherland (best known for playing Buffy's mother Joyce Summers on Buffy the Vampire Slayer) since 1985 and together they have a daughter.