Chatteris United are a professional baseball club based in Chatteris, Ianoia. Formed by steelworks owner Samuel Rountree for his workers to take on a rival steelwork factory in nearby Greasley for a bet, Chatteris United started to play regular exhibition games against other teams following the clubs registration to the Ianoian Baseball Association in 1894. In 1898, Rountree was accused of paying his players, many of whom were given token jobs at the factory on wages considerably higher than the national average. Whilst it was never proven, many teams refused to expel Chatteris United from the IBA as they were most likely doing the same thing.

They are one of the 10 founding members of the Ianoian I-League.

The team plays its home games out of Netherfield which is known for “Triple Alley” in centerfield and the batters difficulty in clearing the fence. On average, the team hits 40% less home runs a year compared to the rest of the division.

Known as the Knights, Chatteris got the nickname in the competitive matches against Greasley Steelworkers, with the winning team claiming a knights helmet as a trophy. The teams played 9, 3-game series between the years of 1891 and 1899 with Chatteris winning 7 of them, including the final 3 series.