Myles grew up in remote communities in Western Australia where his father was a school principal and his mother taught music. Although they moved every two to five years, Myles spent the latter part of his high-school years in Perth.
After graduating from university with a communications degree, Myles moved to Sydney to get an acting agent. He performed King Lear at the New Theatre and realised he needed training. He went back to Perth, auditioned for NIDA and was accepted into their three-year program.
Wildside was his first job, and then he toured with Bell Shakespeare in a version of Romeo and Juliet that explored themes of racism in Australia.
He was packing veterinary products at a wholesale factory when he found out he had the role of Nick Ryan. Myles was "stoked to be given something very Australian with Australian themes," especially in a rural environment, as he loves the country. "I'm an action guy, and doing this series, I get paid to go and play on motor bikes and horses."
Myles graduated from NIDA in 1998, and his television credits include Invincibles, Water Rats, All Saints and Wildside and his current role in McLeods Daughter.