Aayirathil Oruvan (transl. One in a Thousand) is a 1965 Indian Tamil-language swashbuckler film produced and directed by B. R. Panthulu. The film stars M. G. Ramachandran and Jayalalithaa, with M. N. Nambiar, Manohar, Nagesh, S. V. Ramadas, Vijayalakshmi and Madhavi in supporting roles. It revolves around a doctor who is sold into slavery for rebelling against the dictator of his nation, and later forced into a life of piracy.

Aayirathil Oruvan was inspired by many pirate films, particularly Captain Blood (1935), and was Ramachandran's first with Panthulu. It was also the first of many collaborations between Ramachandran and Jayalalithaa. The story and screenplay were written by K. J. Mahadevan, and the dialogues by R. K. Shanmugham. The cinematography was handled by V. Ramamoorthy, and editing by R. Devarajan. The film was shot primarily in Karwar.

Aayirathil Oruvan was released on 9 July 1965. The film emerged a critical and commercial success, running for more than 150 days in theatres. It was a milestone for both Ramachandran and Jayalalithaa, cementing the former's image as a "do-gooder" among the general public, and helping the latter enter politics. A digitised version of the film was released in 2014 and also became a success, running for over 175 days.