The Nassau Stakes is a Group 1 flat horse race in Great Britain which is open to thoroughbred fillies and mares aged three years or older. It is run at Goodwood over a distance of 1 mile, 1 furlong and 192 yards (1,986 metres), and it is scheduled to take place each year in late July or early August.
The event was named in recognition of the friendship between the 5th Duke of Richmond, who owned Goodwood Racecourse, and the House of Orange-Nassau. It was established in 1840, and it was originally restricted to three-year-old fillies only. During the first part of its history it was contested over 1 mile, and this was extended to 1½ miles in 1900. The present distance, about 1¼ miles, was introduced in 1911.
The Nassau Stakes was opened to fillies and mares aged four or older in 1975. For a period it was classed at Group 2 level, and it was then promoted to its current status, Group 1, in 1999. It is now held on the final day of the five-day Glorious Goodwood meeting.