A former high-school quarterback, Meloni worked as a construction worker and bouncer before breaking into acting. He toiled in a number of small film roles and short-lived TV series before a breakout role on Oz in 1998 as a psychotic, bisexual murderer. His raw sexual energy and full-frontal nude scenes made him an audience favorite (especially with gay fans, though he is heterosexual), even though his character was just as likely to kill as kiss. The next year he started on Law & Order: Special Victims Unit as a moralistic but explosive detective and appeared on both shows concurrently until Oz came to an end in 2003. Meloni, who is married with two children, has managed to find time for other acting work, including a supporting role in Nights in Rodanthe (2008) and the voice of the hero in the animated comic-book adaptation Green Lantern: First Flight (2009).
- Left college during his junior year to try to find acting work in L.A., but after six weeks, he returned to Colorado.
- Studied acting at the Neighborhood Playhouse School of the Theatre in New York City.
- Met his wife, production designer Sherman Williams, on an HBO set.
- In 2007, was inducted into his high school's athletic Hall of Fame as a member of the undefeated 1978 football team, for which he was quarterback.
- 2006, Emmy — Outstanding Lead Actor in a Drama Series: Nominee
- Robert Meloni Jr. — Brother
- Sherman Williams — Wife
- Cecile Meloni — Mother
- Michele Meloni — Sister
- Sophia Eva Pietra Meloni — Daughter
- Robert Meloni — Father
- Dante Amadeo Meloni — Son
- University of Colorado, Boulder, Colorado, United States (BA in History, 1983)