Diwan Bahadur Sir Satappa Ramanatha Muthiah Annamalai Chettiar, Raja of Chettinad KCSI (30 September 1881 – 15 June 1948) better known as Raja Sir Annamalai Chettiar was an Indian industrialist, banker, educationist and philanthropist from Tamil Nadu.

Annamalai Chettiar was born on 30 September 1881 at Kanadukathan in the Sivaganga estate of the then Madura district in the Madras Presidency of British India.

In 1916, he transferred from local affairs to the Legislative Council of Madras Presidency, where he sat for 3 years.

Chettiar was given the title Diwan Bahadur by King George V for valuable services rendered to the Crown.

Annamalai Chettiar's oldest son M. A. Muthiah Chettiar, an activist of the Tamil Isai Movement, served as the Minister of Education and excise in the Madras Presidency while his third son M. A. Chidambaram and grandson A. C. Muthiah both served as presidents of the Board of Control for Cricket in India (BCCI).