Amanda Loncar was born on February 26, 1982 in Arcata, California. Loncar attended High School in Sacramento, California. Her father is a surgeon and her mother is a nurse. Loncar moved to New York City at the age of 18 to study with Mike Nichols, George Morrison and Paul Sills at the The New Actors Workshop.
Loncar has appeared in the films "Carlito's Way: Rise to Power", "Building Girl", "Flash", and "Pulling". On television, Loncar has starred in the series "The Loop" and had a recurring role in "The Bedford Diaries". She has also made guest appearances on "Law & Order: Criminal Intent" and "CSI: Miami".