Grenier was raised in Brooklyn, New York by his mother, Karesse Grenier, a real estate agent. His mother met his father, John Dunbar (no relation to the British artist, collector, and gallerist), in a commune in the 1970s and the two were never married. Grenier is of Apache Native American,Irish and European descent. He attended Fiorello H. LaGuardia High School of Music & Art and Performing Read more...

In 1997, Grenier made his film debut in the independent drama Arresting Gena. In 1999, he played opposite Melissa Joan Hart in Drive Me Crazy as well as in Britney Spears' music video "You Drive Me Crazy", and in 2001, starred in James Toback's Harvard Man. In 2002, Grenier made his directorial debut with the documentary, Shot in the Dark. The documentary chronicles his years-long search for his Read more...

In 2005, Grenier began dating Sports Illustrated swimsuit model Melissa Keller. The couple dated on and off for two years.

In August 2007, Grenier was rumored to be dating socialite Paris Hilton after he was photographed at her home in Malibu while shooting a documentary he is producing about paparazzi. Grenier denied the rumors in an interview on The Howard Stern Show.

In 2008, Grenier Read more...