2018 Thai League 3 Lower Region  2018 Thai League 3 Lower Region is the 2nd season of the Thai football league. It is a part of the Thai League 3 and the feeder league for the Thai League 2. A total of 14 teams will compete in the league this season, after Banbueng withdrew before the season started. A club was promoted from the 2017 Thai League 4  A clubs was promoted to the 2018 Thai League 2  A club was relegated to the 2018 Thai League 4 Western Region  A club was relegated from the 2017 Thai League 2       A T3 team could registered five foreign players by at least one player from AFC member countries and at least one player from ASEAN member countries. A team can use four foreign players on the field in each game, including at least one player from the AFC member countries or ASEAN member countries (3+1). Source: Thai League 3 Note: Some error of T3 official match report 28 July 2018 (Trang 3–1 Ranong United). Some error of T3 official match report 5 August 2018 (Nara United 7–0 Simork).