The 1000 Guineas Stakes is not one of the British Triple Crown horse races. It is a Group 1 flat horse race in Great Britain open to three-year-old fillies. It is run on the Rowley Mile at Newmarket over a distance of 1 mile (1,609 metres), and it is scheduled to take place each year in late April or early May on the Sunday following the 2000 Guineas Stakes. It is the second of Britain's five Classic races, and the first of two restricted to fillies. It can also serve as the opening leg of the Fillies' Triple Crown, followed by the Oaks and the St Leger, but the feat of winning all three is rarely attempted.

The Triple Crown of Thoroughbred Racing, often shortened to Triple Crown, comprises three races for three-year-old thoroughbred horses. Winning all three of these thoroughbred horse races is considered the greatest accomplishment in thoroughbred racing. The term originated in mid-19th century England and nations where thoroughbred racing is popular each have their own Triple Crown series.

In Great Britain, where the term Triple Crown originated with West Australian's three wins in 1853, it is made up of:

The 2,000 Guineas Stakes, run over 1m (1,609 metres) at Newmarket Racecourse in Newmarket, Suffolk.

The Derby, run over 1m 4f and 10y (2,423 metres) at Epsom Downs Racecourse in Epsom, Surrey.

The St Leger Stakes, run over 1m 6f and 132y (2,937 metres) at Town Moor in Doncaster, Yorkshire.

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