| Thirachai Nakwanich | |
| Honorific-Suffix: | MPCh MWM |
| Native Name: | ธีรชัย นาควานิช |
| Native Name Lang: | th |
| Office: | Privy Councillor |
| Term Start: | 6 December 2016 |
| Term End: | 19 June 2018 |
| Office1: | Commander-in-chief of the Royal Thai Army |
| Predecessor1: | Udomdej Sitabutr |
| Successor1: | Chalermchai Sitthisart |
| Term Start1: | 1 October 2015 |
| Term End1: | 30 September 2016 |
| Commands: | Commander in Chief (Army) |
| Serviceyears: | 1978–2016 |
| Birth Date: | 15 November 1955 |
| Birth Place: | Bangkok, Thailand |
| Spouse: | Boonraksa Nakwanich |
| Children: | 2 |
| Allegiance: |  Thailand |
| Rank: | General |
| Battles: | Communist insurgency in Thailand |
| Mawards: |
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General Thirachai Nakawanich PC (Thai: ธีรชัย นาควานิช, born 15 November 1955) is a Thai military officer who served as Commander-in-Chief of the Royal Thai Army from 2015 to 2016.[1] He succeeded Udomdej Sitabutr, with whom he has had a long-running feud, and whose preferred successor would have been Preecha Chan-ocha, brother of Prime Minister and NCPO chief Prayuth Chan-ocha.[2] He was succeeded in 2016 by General Chalermchai Sitthisart upon reaching retirement age.
Thirachai completed secondary education at Patumwan Demonstration School, Srinakharinwirot University. He then decided to go into a military career and proceeded to study at Armed Forces Academies Preparatory School (Class 14) and Chulachomklao Royal Military Academy (Class 25).[3]
Thirachai started duty in the 2nd Infantry Regiment, Queen Sirikit's Guard knowns as Burapha Payak (Eastern tigers). In 2013, he appointed as commander of the 1st Army Area. Then in 2015 he was appointed as Commander-in-chief of the Royal Thai Army inheriting the position from General Udomdej Sitabutr.
During 2014 Thai coup d'état, He was commander of the peacekeeping force of National Council for Peace and Order.[4]
He used to go to work in the field in the three southern border provinces as the commander of the Narathiwat Special Task Force.[5]
In December 2016 he was appointed to the Privy Council by King Vajiralongkorn, but was relieved of his duties in June 2018 for unspecified reasons.[6]