The World Series Of Mahjong (Chinese: 世界麻将大赛) was a privately sponsored Mahjong tournament. Both men and women were eligible to contest this title, and the top finishers received prize money with the champion also receiving a necklace. The tournament system competition took place over a few days. Contestants had to pay an entry fee and provide proof that they were at least the age of 21.

The World Series Of Mahjong (WSOM) was established by World Mahjong Ltd.(WML) in 2007. Chunglai Hui, a designer from Hong Kong, won the first tournament. Following tournaments were held in 2008, 2010, and 2015.

The rules for the tournament were developed by Alan Kwan as a slight modification of his Zung Jung (中庸) pattern-based scoring system. The tournament used sets of 136 tiles, excluding the bonus flower tiles, and pairs of dice. Prevailing wind was not recognized.

The names are ordered as Given name and Surname.