Dean was named by his uncle after the Oscar winning 1950s American actor Dean Jagger and chose for himself the same profession. Dean began acting in school productions at age 14 after a chance meeting with actor Michael Douglas while on holiday. After finishing school, Dean heeded the call of his athletic talent and became a pro skater, competing and placing in events such as the X-Games. He returned to his native England to fulfill his driving desire to act. He joined British Actors' Equity and studied in London at The Actors Centre and Penelope Jay's School of Performing Arts.