Callan was born in Sydney, Australia. He attended Scots College, an all boys school in Bellevue Hill, where he was the head chorister and topped the London Trinity musical theatre exams.
He was a track athlete until he was injured, leading him to study acting and to move to Los Angeles to be in movies and TV Series.
- Franswa Sharl
- I Am Number Four
- Underground: The Julian Assange Story
- The Great Gabsty
- Beneath the Harvest Sky
- Robot Overlords
- Callan's great-great-great-grandfather, Joseph Augustus Henriques, was the first USA Consul to Australia. Appointed by the President of the United States, Henriques originally resided in his home on 5th Avenue, New York. He took up his position to represent the USA in Australia in Melbourne in 1852. Callan was named after Joseph's grandson (Callan's great-grandfather), Claude Augustus Henriques. Callan's full name is Callan Ryan Claude McAuliffe.
- Callan was the Youth Ambassador to The Wolf Connection. A non-profit organization which works with wolves and wolf-dogs in programs to help 'at-risk' teenagers in the Greater Los Angeles Area. Callan was a hands-on Ambassador, using his weekends to train with the wolf-dogs. When he wasn't filming, he assisted in the programs led by trained counselors.