Born and raised in London. Gatt first got the acting bug when his Maltese parents took him to see Star Wars at the age of 8 and he decided to be Han Solo when he was older. He began his professional training at Sylvia Young Theater School and then followed that with a 3 year acting and music theater course at the Mountview Academy of Theater Arts, graduating with a degree. He has a brief stint in the British Royal Marines.
He quickly found work in the West End, starring in productions including "Miss Saigon" and "Jesus Christ Superstar." After moving to the U.S., he immediately booked a lead role in the thriller feature, "Pulse," opposite Kristen Bell.
Gatt is perhaps best known as the motion capture performer and likeness for 'Kratos' from the acclaimed "God Of War" video game franchise as well as the voice of 'Lord Scourge' in the hugely popular "Star Wars: The Old Republic." He most recently (2011) appeared as the Frost Giant villain, 'Grundroth' in Marvel's box-office smash "THOR," and will next been seen portraying humanoid Starfleet 'Science Officer 0718' in the highly anticipated sequel, "Star Trek Into Darkness" from J.J. Abrams.
Additionally, Gatt's notable television guest star credits include NBC's "Chuck," Fox's "Breaking In," Adult Swim's "Eagleheart," David E. Kelley's "Wonder Woman" pilot for NBC and a fan-favorite recurring arc on Cinemax's new (2012) hit series, "Banshee."
He resides in Los Angeles.
Gatt has a condition called alopecia universalis which made all of his hair fall out at the age of 14.