Yönetmen : Luc Besson Oyuncular : Natalie Portman, Jean Reno, Gary Oldman, Samy Naceri, Elizabeth Regen Senaryo : Luc Besson Yapımcı : Luc Besson, Patrice Ledoux

Mathilda, New York'ta yaşayan ailesi dağılmış 12 yaşında küçük bir kızdır. Ailesini sevmeyen Mathilda için en değerli varlığı küçük kardeşidir. Babası uyuşturucu işlerine bulaşınca mafya ailenin tüm bireylerini öldürür. O sırada alışverişte olan Mathilda ise olaydan kılpayı kurtulur ve Leon'un kaldığı daireye saklanır. Leon ise çok soğukkanlı bir katildir. Ancak Mathilda'ya karşı içten bir sevgi besler ve ona kol kanat gerer. Aslında babalık, arkadaşlık gibi kavramlar ona çok yabancıdır. Mathilda, a twelve-year old New York girl, is living an undesirable life among her half-family. Her father stores drugs for two-faced cop Norman Stansfield. Only her little brother keeps Mathilda from breaking apart. One day, Stansfield and his team take cruel revenge on her father for stretching the drugs a little, thus killing the whole family. Only Mathilda, who was out shopping, survives by finding shelter in Léon's apartment in the moment of highest need. Soon, she finds out about the strange neighbour's unusual profession - killing - and desperately seeks his help in taking revenge for her little brother. Léon, who is completely unexperienced in fatherly tasks, and in friendships, does his best to keep Mathilda out of trouble - unsuccessfully. Now, the conflict between a killer, who slowly discovers his abilities to live, to feel, to love and a corrupt police officer, who does anything in his might to get rid of an eye witness, arises to unmeasurable proportions - all for the...