The club began as an adult softball team in 1988 and were initially called the London Millions. The adult club began organising and training a separate baseball programme for young people in the Park in 1995 under the name London Meteorites. The club entered a team into the BBF National Baseball League for the first time in 2007, with the newly named London Mets ending their inaugural season as national champions. A second championship followed a year later and the club began to expand in 2008 with the creation of AAA London Metros, and in 2009 when the London Marauders were formed to enter the BBF A League.

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The 2010s saw the club continue to expand, introducing teams at every level of play in the BBF and starting the popular Baseball for Beginners program which has grown rapidly. The middle of the decade begun an era of dominance of British Baseball with the Mets winning their third national championship in 2015, before starting an historic run of success in 2017 which has seen the Mets secure 9 consecutive NBL championships.

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The success of the London Mets has carried over into the 2020s as well as the expansion of the club, with the youth program continuing to grow, making baseball accessible to players from ages 5-16. In 2021 the London Mayhem team was formed to participate in the BBF women's league. In 2022 the Canal League was created to give casual and new to the game adults a fun while competitive league to play in.