Father is noted Maine landscape painter Neil Welliver.
Made professional acting debut in the 1990 action/adventure movie Navy Seals.
Made TV debut in the 1990 TNT movie The Lost Capone; played Al Capone a year later in the theatrical movie The Mobsters.
Connection with writer/producers Steven Bochco and David Milch began with a guest role on a 1992 episode of L.A. Law. Also guested on three 1996 episodes of Murder One, was a semiregular on NYPD Blue (1995-98), and a regular on Brooklyn South (1996-97), Big Apple (2001) and Deadwood (2004-06).
Laurence Fishburne was best man at his 1998 wedding.
Appeared with Lost rival Mark Pellegrino in Twisted. The two also appeared in consecutive episodes of Prison Break (2008) and Supernatural (2009).
A landscape painter himself, he has exhibited at galleries in Maine and Los Angeles.
2006, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
Quinnn M. Welliver — Son
Neil Welliver — Father
Eli Welliver — Brother
Ashley Welliver — Sister
Joanna Heimbold — Ex-wife
Silas Welliver — Brother
Mimi Martin Welliver — Stepmother
Jose Stemkens — Wife
Eamonn Lorcan Charles Welliver — Son
Cora McBride Walling Welliver — Daughter
Elizabeth W. Alexander — Wife (deceased)
Norma Cripps — Mother
Ethan A. Welliver — Brother
John W. Welliver — Half Brother
Attended Bennington College, Bennington, Vermont, United States; New York University, New York, New York, United States (BA in Drama)
Birth Place: New Haven, Connecticut, United States