Ali Baba (Arabic: علي بابا ʿAlī Bābā ) is a character from the folk tale Ali Baba and the Forty Thieves (علي بابا والأربعون لصا). This story is included in many versions of the One Thousand and One Nights, to which it was added by Antoine Galland in the 18th century. It is one of the most familiar of the "Arabian Nights" tales, and has been widely retold and performed in many media, especially for children, where the more violent aspects of the story are often suppressed.
In the story, Ali Baba is a poor woodcutter who discovers the secret of a thieves' den, entered with the phrase "Open Sesame". The thieves learn this and try to kill Ali Baba, but Ali Baba's faithful slave-girl foils their plots. Ali Baba gives his son to her in marriage and keeps the secret of the treasure.