The League of Legends SEA Tour (LST) was a professional League of Legends esports tournament in Southeast Asia that was founded in 2018 by Garena as a replacement for the Garena Premier League (GPL). The competition consisted of teams who qualified through the LST qualifiers of each minor region: Indonesia–Malaysia–Singapore, Philippines, and Thailand. Winners of the LST represented Southeast Asia at the Mid-Season Invitational and World Championship.

It was announced in September 2019 that the LST would be merged with the League of Legends Master Series (Taiwan/Hong Kong/Macau) to create a new professional league for all Garena-affiliated regions (excluding Vietnam), the Pacific Championship Series (PCS).

In 2019, based on the League of Legends local servers in Southeast Asia that have been released by Garena, LST is divided into some minor regions. Each region will have one spot in the spring season, while in the summer season it will be decided based on the results of the spring season.

In May 2019, Indonesia's local server for League of Legends was closed by Garena. Indonesian players were transferred to the SAM server (Singapore & Malaysia) and Indonesia was merged with Malaysia–Singapore to form a single minor region for the 2019 Summer Season.

Ranked Qualifier (Stage 1):

National Qualifier (Stage 2):

Main Season – Group Stage (Stage 3):

Main Season – Play-off Stage (Stage 4):