Chelmsford City racecourse, originally known as Great Leighs Racecourse, is a thoroughbred horse racing venue located in Great Leighs near Chelmsford, Essex, England. When it opened in April 2008, it was the first entirely new racecourse in the UK since Taunton opened in 1927. It went into administration in January 2009, and racing did not resume until January 2015.
Chelmsford City (known as Great Leighs at the time) was developed and owned by entrepreneur John Holmes and his son, Jonathan. It aimed to exploit potentially the largest unserved market in British horseracing. Overall there is slightly more than one racecourse per million people in Great Britain, but there was no racecourse in Essex (population >1.6 million), in east London (formerly in part, part of Essex) or in the neighbouring county of Hertfordshire (population >1 million). The new course is only 50 miles (80 kilometres) from Newmarket, the largest racehorse training centre in Britain. The course is laid out as an 8.5-fong (1,700-metre) left-handed Polytrack oval, with a 2-fong (400-metre) home straight. The 10,000-capacity grandstand was used at the 2006 Ryder Cup.