Ian Matthias Bavitz (born June 5, 1976), better known by his stage name Aesop Rock, is an American rapper and producer from Long Island, New York. He was at the forefront of the new wave of underground and alternative hip hop acts that emerged during the late 1990s and early 2000s. He was signed to El-P's Definitive Jux label until it went on hiatus in 2010. In a 2010 retrospective, betterPropaganda ranked him at number 19 at the Top 100 Artists of the Decade.

He released his first album, Music for Earthworms, in 1997, with Float following three years later. Labor Days, his third studio album, was released in September 2001. His next release, titled Bazooka Tooth, released 2 years later in September 2003. His fourth studio album, None Shall Pass, was released in August 2007. Its titular song became one of Ian's most popular and well-known songs. His sixth record, Skelethon, was released in July 2012. His seventh release, The Impossible Kid, came out in April 2016. His eighth album, Spirit World Field Guide, came out in November 2020, with his ninth album, Garbology, released in November 2021. Integrated Tech Solutions, his tenth album, was released in November 2023.

He was a member of the groups The Weathermen, Hail Mary Mallon, and the Uncluded, and is currently the vocalist of duo Malibu Ken.

Regarding his name, he said: "I acquired the name Aesop from a movie I had acted in with some friends. It was my character's name and it sort of stuck. The rock part came later just from throwing it in rhymes."