Sitthichai Sitsongpeenong is a Thai Muay Thai kickboxer who is currently signed to ONE Championship. Sitthichai is a former Lumpinee Stadium Welterweight Champion and Glory Lightweight Champion. Combat Press ranks him as the #3 lightweight kickboxer in the world. As of October 27, 2022, he is ranked #3 in the ONE Featherweight Kickboxing rankings, and as of March 6, 2023, he is ranked #2 in the ONE Featherweight Muay Thai rankings.

Lumpinee Boxing Stadium is a sporting arena in Bangkok, Thailand. Opened more than a decade later than Rajadamnern Stadium, Lumpinee is run by the Royal Thai Army. It has become the symbol of modern Muay Thai. Only Rajadamnern Stadium rivals the prestige of holding the title of "Muay Thai Champion of Lumpinee". The ranking system and championship titles are held from mini flyweight (105 lb) up to super welterweight (154 lb).