Thongchai or Tongchai are romanizations of two homophonous Thai names, and (). Both are masculine given names, and also a surname.
Given name People with the given name Thongchai () include: Thongchai Akkarapong, footballer Thongchai Jaidee, golfer Thongchai Sitsongpeenong, Muay Thai boxer Thongchai Sukkoki, footballer Thongchai Winichakul, historian Tongchai Teptani, boxer Thongchai Yenprasert, politician
People with the given name Thongchai () include: Thongchai McIntyre, singer Thongchai Rathchai, footballer
Surname People with the surname Thongchai () include: Suradech Thongchai, footballer
People with the surname Thongchai () include: Pipob Thongchai, political activist