The 2,000 Guineas Stakes is a Group 1 flat horse race in Great Britain open to three-year-old thoroughbred colts and 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.
It is one of Britain's five Classic races, and at present it is the first to be run in the year. It also serves as the opening leg of the Triple Crown, followed by the Derby and the St Leger, although the feat of winning all three has been rarely attempted in recent decades.
The 2,000 Guineas was first run on 18 April 1809, and it preceded the introduction of a version for fillies only, the 1,000 Guineas, by five years. Both races were established by the Jockey Club under the direction of Sir Charles Bunbury, who had earlier co-founded the Derby at Epsom. The races were named according to their original prize funds (a guinea amounted to 21 shillings, or £1.05).
By the mid-1860s, the 2,000 Guineas was regarded as one of Britain's most prestigious races for three-year-olds. The five leading events for this age group, characterised by increasing distances as the season progressed, began to be known as "Classics". The concept was later adopted in many other countries.