A woman was assaulted after getting into an argument at Wicksteed Park.
A police spokesman said an argument broke out between two women within the pleasure ground in the park and one of the women assaulted the other before leaving the scene.
The offender was white, with reddy brown hair, and she wore leopard-skin leggings.
Police are appealing for witnesses to the incident which took place between 4.15pm and 4.30pm on Monday, July 9.
Anyone with information about the assault can call Northamptonshire Police on 101 or information can be given anonymously to Crimestoppers on 0800 555111.