kollmar was born in brooklyn, new york to john and christine l. (née smith) kollmar. his great-great grandfather was daniel d. tompkins, the fourth governor of new york and the sixth vice president of the united states. the kollmars moved to ridgewood, new jersey where john kollmar worked as an architect. kollmar later attended tusculum college where he became interested in acting. while in college, he performed in the school's glee club and was the editor of the school newspaper. upon graduation, he enrolled at the yale school of drama but dropped out after winning a role on a radio drama.