Wikipedia - Thai League 4

Thai League 4 (Thai: ไทยลีก 4), commonly known as the T4, was the fourth level association football league in Thailand. In 2009, it was divided into five groups by geographic region. Each group contained 16 clubs except for the Southern Region group which contained 13 clubs. It was sponsored by AIS and therefore officially known as the AIS Regional League Division 2. In 2016, Khor Royal Cup became a trophy for Regional League Division 2.

In 2017, Football Association of Thailand rebranded the league to Thai League 4.

Thailand Division 4 is an exciting and competitive soccer tournament that showcases emerging talent and local clubs across Thailand. As part of the country's football development structure, Division 4 serves as a platform for smaller teams to demonstrate their skills, gain experience, and aspire to climb the ranks into higher divisions. The tournament features passionate players, vibrant communities, and thrilling matches that highlight the growing popularity of football at the grassroots level in Thailand. With a focus on fostering local talent and promoting the sport nationwide, Thailand Division 4 is an essential stepping stone in the country's football journey.