The 2009–10 RFU Championship was the 1st season (of the professionalised format) of the second division of the English domestic rugby union competitions, played between August 2009 and May 2010. The league had been restructured from the 16 teams of the previous season down to just 12. New teams included Bristol who had been relegated from the Guinness Premiership 2008–09 and Birmingham and Solihull who had been promoted from National Division Two 2008–09. As well as a decrease in teams, the league would now consist of three parts - a standard league section, promotion/relegation pools and then playoffs to determine who would go up as champions.