Gigandet was born in Tacoma, Washington to Jay and Kim Gigandet, along with one sister named Kelsie. After graduating from Auburn Senior High School in Auburn, Washington in 2001, he moved to California where he attended Santa Monica Community College, where he first took an acting class.

In 2003, Gigandet won his first role and made his TV debut with his portrayal of Mark Young on the fourth season of CSI: Crime Scene Investigation. His other television credits include The Young and the Restless, Jack & Bobby and The O.C., where he played Kevin Volchok.

He also starred in the film Mistaken in 2004, Who's Your Caddy? in 2007, and both Never Back Down and Twilight in 2008. Gigandet has a number of newer film roles, including The Unborn and Making Change.

In 2008, Gigandet was honored with several awards, including the "One to Watch" award received at the 10th Annual Young Hollywood Awards. He also shares a MTV Movie Award with co-star Sean Farisfor "Best Fight" from the movie Never Back Down. His latest accomplishment is the "Rising Male Star of the Year" award, given to him by Home Entertainment.

Gigandet enjoys basketball, golf, skiing, surfing, and krav maga, a self defense system developed by the Israeli army. He and his girlfriend, actress Dominique Geisendorff, had a baby girl on April, 14 2009.