| Thanong Bidaya | |
| Native Name Lang: | th |
| Nationality: | Thai |
| Office: | Finance Minister of Thailand |
| Term Start: | 21 June 1997 |
| Term End: | 24 October 1997 |
| Predecessor: | Amnuay Weerawan |
| Successor: | Kosit Panpiemras |
| Term Start1: | 3 August 2005 |
| Term End1: | 19 September 2006 |
| Predecessor1: | Somkid Jatusripitak |
| Successor1: | Pridiyathorn Devakula |
| Office2: | Minister of Commerce |
| Term Start2: | 11 March 2005 |
| Term End2: | 2 August 2005 |
| Predecessor2: | Somkid Jatusripitak |
| Successor2: | Watana Muangsook |
| Birth Name: | Thanong Lamyai |
| Birth Date: | 1947 7, df=yes |
| Birth Place: | Suphan Buri, Thailand |
| Party: | Thai Rak Thai Party |
Thanong Bidaya (th|ทนง พิทยะ;), born Thanong Lamyai, is a Thai politician and deposed finance minister. After the military overthrew the government of Thaksin Shinawatra, he remained in Singapore where he was attending the annual meeting of the World Bank/International Monetary Fund.
Thanong was born in Suphanburi Province. He has four siblings, all of whom are teachers. Thanong was the only boy in his village to earn a bachelor's degree. He later earned a PhD.
Thanong became the Dean of the Graduate School of Business Administration or NIDA Business School, National Institute of Development Administration (NIDA). He also worked for a time as a researcher at the World Bank in Washington, D.C.
He later left his academic career for a career in business, citing insufficient income. From April to August 2007, Thanong was a visiting professor at the International Graduate School of Social Sciences, Yokohama National University, Japan.
Thanong became president of Thai Military Bank.
Thanong was invited by the government of Premier Chavalit Yongchaiyudh to be finance minister from June to October 1997, the height of the Asian financial crisis.
He served as finance minister in the government of Thaksin Shinawatra for a second term from August 2005 until the military coup of September 2006.