Newmarket Heath is a 279.3-hectare-large (690-acre) biological Site of Special Scientific Interest in Newmarket in Suffolk.

It covers most of Newmarket Racecourse.

[1][2] Most of this site is chalk grassland, and it has areas of chalk heath, a rare habitat in Britain.

There is a rich variety of flowering plants, including a nationally rare species listed in the British Red Data Book of threatened species and five nationally uncommon ones.

The dominant grasses are upright brome and sheep's fescue.