Gonzalez was born in San Antonio, Texas, where he was a student at Central Catholic High School. He became an accomplished cross-country and track runner, winning the Texas State Championship in the mile and two mile. After graduating in 1994 and turning down a presidential appointment to West Point, Nicholas pursued an English degree at Stanford University in California. His interest and love of literature, history, and poetry led him to two terms at Oxford University in England. The following summer, he returned to Europe on a research grant where he studied with scholars at Oxford and Trinity College, Dublin to complete his thesis on James Joyce’s Ulysses. While finishing his Bachelor of Arts in English in 1998, Nicholas was approached to do a one-man theatre piece called Gas by María Irene Fornés. Alma Martinez, an actress and Stanford professor, encouraged him to become a professional actor. With her help, he connected with the theatrical movement in San Francisco. He polished his skills by performing in classic and contemporary theatre. “I’m happy when I’m on stage,” he declares. Gonzalez is of Mexican descent.
Gonzalez enjoys playing golf, video games, poker (finished 2nd at the World Poker Tour Celebrity Invitational in 2009) and working out. He is an avid reader, consuming as many as eight books a week. He also volunteers with organizations such as the National Hispanic Institute and The Friends of El Faro. He was romantically involved with American actress Regina King in 2007. Gonzalez is a supporter of animal rights and PETA. He posed for PETA's campaign "If you wouldn't wear your dog, please don't wear fur" advertisement. Nicholas married his longtime girlfriend Kelsey Crane on Saturday, April 16, 2016.