Officers remain on the scene carrying out enquiries.
The park is taped off and multiple police vehicles are in the area.
A police spokesperson said: “Officers are currently conducting enquiries in Houndwell Park in connection with an allegation of rape.
“It was reported to police that a 17-year-old girl was assaulted shortly after 10am this morning (Thursday, November 12).
“The investigation is in its very early stages and remains ongoing.
“Officers are at the scene and will be in the area today conducting enquiries.”
Anyone in the area at the time and who witnessed anything suspicious is urged to call police on 101 quoting reference 44200438513.
Alternatively, they can call Crimestoppers anonymously on 0800 555 111.