Ewing was born in Manly and grew up in Forestville near Sydney, Australia and is the eldest of four children. He attended Marist College North Shore where he performed in musicals years throughout high school. He is the first ever professional actor in his family and trained with John Gibson in Sydney's North Shore. Ewing has two tattoos on his right arm. The first is a Southern Cross as a mark of respect to his ancestors who fought in two World Wars. The second says Carpe Diem, which directly translates as "Seize the Day". Ewing's interpretation is "Have a crack".