[5][6] A native of Seoul, Ahn was the son of a veteran filmmaker and producer and started out as a child actor, appearing in director Kim Ki-young's celebrated film The Housemaid (1960).

He and Park Joong-hoon starred in the 1993 hit buddy cop-comedy Two Cops and won the "Daesang" (Grand Prize) at the Baeksang Arts Awards.

[14][16] He and his Two Cops co-star Park Joong-hoon reunited for the 2006 film Radio Star, directed by acclaimed director Lee Joon-ik.

Despite stiff competition from Tazza: The High Rollers, which was released on the same day, it was still a critical and commercial success, with Park and Ahn being nominated for or winning several awards.

[21][22][23] Ahn surprised critics and commentators by appearing in the low-budget semi-biographical 2011 film Unbowed since it had been rejected by major distributors due to its controversial content.

It was released to minimal fanfare but quickly became a sleeper hit due to its "David and Goliath" storyline which resonated with viewers.

[32] On 23 June 2012, Ahn and Lee Byung-hun became some of the first Korean actors to leave their hand and foot prints on the forecourt of Grauman's Chinese Theatre in Hollywood, Los Angeles.

[40][41][42] Because of his ability to speak several foreign languages, UNICEF appointed Ahn as a representative, and his image is often seen in advertisements on planes travelling to Korea.