Who played Léon in "Léon: The Professional"?

"Léon: The Professional", titled "Leon" in the UK and Australia (and originally titled "The Professional" in the US), is a 1994 English-language French action thriller film written and directed by Luc Besson. It stars Jean Reno, Gary Oldman, and Natalie Portman (in her film debut). The plot follows Léon (Reno), a professional hitman, who reluctantly takes in 12-year-old Mathilda (Portman), after her family is murdered by corrupt Drug Enforcement Administration agent Norman Stansfield (Oldman). Léon and Mathilda form an unusual relationship, as she becomes his protégée and learns the hitman's trade.

"Léon: The Professional" received positive reviews from critics. The film holds a 72% positive aggregate rating based on 61 critical reviews on Rotten Tomatoes with an average rating of 6.7/10. The site's consensus states, "Pivoting on the unusual relationship between seasoned hitman and his 12-year-old apprentice — a breakout turn by young Natalie Portman — Luc Besson's Léon is a stylish and oddly affecting thriller". At Metacritic, the film received an average score of 64 based on 12 reviews, indicating "Generally favorable reviews".