Born in Roseau, Minnesota, Garrett spent his early years growing up on a farm in a small town. When he was in the ninth grade his family moved to Scottsdale Arizona, where he began taking private acting lessons. After graduating high school, he immediately moved to Los Angeles to pursue and acting career.

One month later, he'd landed the role of Achilles' cousin Patroclus in the major motion picture Troy (2004) opposite Brad Pitt. His next feature was Friday night lights (2004) starring Billy Bob Thornton, in which Garrett played a high school football player.

He then landed a starring role opposite Mark Wahlberg in Four Brothers (2005), playing one of four brothers whose mother is murdered.
Modeled for L.L. Bean and Teen Magazine before acting. Won the role of Patroclus in Troy only one month after arriving in Los Angeles to pursue an acting career. Grew up as a huge fan of Tim McGraw only to have him play his father in Friday Night Lights Gained at least 30 lbs. of muscle for the role of Patroclus in Troy, then gained another 20 for the role of Don Billinsley in Friday Night Lights - only to slim back down for the role of Jack Mercer in Four Brothers Ran track in high school Has a brother and a sister Graduated a semester early from Horizon High school in Phoenix, Arizona Participated in wrestling and football during high school Family: mother Kristi, father Robert, older brother Nathaniel, and older sister Amanda. Nominated for Choice Breakout Movie Star - Male for "Troy" in the 2004 Teen Choice Awards. Is a huge fan of punk rock. Parents divorced when he was a young boy. Participated in ice skating, wrestling, and football in high school. Grew up on a farm that only got one radio station, that played country music. The airwaves were dominated by Tim McGraw, who later went on to star as his father in "Friday Night Lights" . Enjoys hunting and the outdoors. When he was 15, went to various punk rock shows to photograph the bands, and their fashions. Current residence: In an apartment in LA (which he bought with the money he made from Troy). He enjoys staying at home and cooking pasta He attended Horizon High School, but graduated a semester early to pursue acting.