The 2021 British J-Cup was the fourth British J-Cup professional wrestling tournament produced by Revolution Pro Wrestling (RPW), which took place on at the Gordon Craig Theatre in Stevenage, Hertfordshire, England.
The tournament final was a four-way elimination match, which Mike Bailey won by defeating Michael Oku, Connor Mills and Luke Jacobs. Apart from the tournament, United Empire (Kyle Fletcher, Mark Davis and Will Ospreay) defeated Ricky Knight Jr. and Sunshine Machine (Chuck Mambo and TK Cooper) in a six-man tag team match, and Yota Tsuji defeated Big Damo.
On September 25, 2021, RPW announced on its official Twitter account that the British J-Cup would return after a two-year hiatus, being held at the at the Gordon Craig Theatre in Stevenage, Hertfordshire, England. The British J-Cup was last held in 2019, and there was no tournament in 2020 due to the COVID-19 pandemic.
The qualifying matches for British J-Cup were held at Unfinished Business on at Priory Center in St Neots, Cambridgeshire.
Ian Hamilton of 411Mania praised the event, scoring it 8.0. According to him, it was "A largely stand-alone show". He stated that "the 2021 British J-Cup more than delivered in the tournament format - while the pair of non-tournament matches on show provided plenty of spectacle as well."
By winning the British J-Cup, Mike Bailey earned a British Cruiserweight Championship match against Michael Oku at Uprising, which Bailey lost.
The tournament brackets for the British J-Cup were as follows: