The 2021 WST Pro Series was a professional ranking snooker tournament, taking place from 18 January to 21 March 2021 at the Marshall Arena in Milton Keynes, England. The event featured 128 players, and was played over three stages of round-robin groups of eight players, with the Final Group winner as the tournament champion.

Seven-time World Champion, Stephen Hendry, was due to make his return to the professional snooker tour, having initially retired in 2012. However, he withdrew before the tournament began.

Gary Wilson made his third career maximum break in the second frame of his Group G match with Liam Highfield.

Mark Williams won the only edition of the event, winning the 23rd ranking title of his career on his 46th birthday, becoming the third oldest ranking event winner behind Welsh compatriots Doug Mountjoy who was 46 in 1989 and Ray Reardon who was 50 in 1982.

There were 128 players taking part in the event. In the tournament's first stage players were divided into 16 groups of each eight players, with the top two players of each group advancing to the second group stage. The tournament draw was conducted on 8 January 2021.

The second group stage consisted of four groups, also of each eight players, with the top two players of each group advancing to the final group.

The winner of the final group were crowned as tournament champion.

All matches were played as best of three frames, and players were ranked, using the following criteria: