| A. K. S. Usgaonkar | |
| Birth Name: | Achyut Kashinath Sinai Usgaonkar |
| Birth Date: | 15 September 1928 |
| Birth Place: | Khanapur, Kingdom of Mysore, British India |
| Office1: | Member of Vidhan sabha, Goa |
| Office2: | Deputy Speaker of Vidhan Sabha, Goa |
| Termstart2: | 15 January 1964 |
| Termend2: | 28 March 1966 |
| Successor2: | Mamdali Jiwani |
| Predecessor2: | established |
| Party: | Maharashtrawadi Gomantak Party |
| Predecessor1: | constituency established |
| Constituency1: | Pale |
| Termstart1: | 1963 |
| Termend1: | 1977 |
| Successor1: | Laxmikant Surlikar |
| Alma Mater: | Peoples High School, Panaji |
| Death Place: | Bambolim, Goa, India |
| Children: | Varsha Usgaonkar (daughter) |
| Spouse: | Manikabai |
Achyut Kashinath Sinai Usgaonkar (15 September 1928 – 16 June 2020)[1] was an Indian politician who served as the leader of the Maharashtrawadi Gomantak Party. He served as cabinet rank minister in the Shashikala Kakodkar ministry of Goa, Daman and Diu from 13 August 1977 to 27 April 1979. Prior to that, Usgaonkar was deputy minister in the Dayanand Bandodkar ministry and was also deputy speaker of the Goa, Daman and Diu Legislative Assembly.
Usgaonkar secured victory in the Pale Assembly Election of 1967, garnering a total of 5671 votes.[2]
He lived in the Miramar beach area in Panaji.
Usgaonkar's daughter Varsha Usgaonkar is a noted film actress.[3]
Usgaonkar died after a long illness at the Goa Medical College in Bambolim on 16 June 2020.[4]