Julian is the oldest of the Five and is said to be 12 in the first book (out of 21) and is said in The Famous Five - Five on a Treasure Island that he lives in London with his mother, father and two younger siblings - Dick and Anne. He is seen as the most responsible of the group and takes care of his siblings and cousin. He is considered to be the leader of the Famous Five adventuring group.
- Birth Name: Julian Barnard (this is never made clear - some believe that his last name could be Kirrin)
- Age: 12 (FOATI - FGAA) 13 (FRAT - present)
- Siblings: Dick Barnard (younger brother), Anne Barnard (younger sister)
- Cousins: George Kirrin
- Uncles: Quentin Kirrin
- Aunts: Fanny Kirrin
- First Appearance: Five On A Treasure Island
- Final Appearance: Five Are Together Again
- Julian has straight, short blonde hair and brown eyes.
- He usually wears a sleeveless jersey and beige short trousers, along with a yellow or white shirt and brown shoes.