Police have made an arrest after the incident in Butland Road between 10.30am and 10.45am on Saturday (September 21).
The woman was running near Lakelands Hospice when the man exposed himself to her.
A police spokesman said: "The man was described as white, between 23 and 25-years-old, about 5ft 7in tall and of slim build.
"He had dark brown hair and stubble.
"He was wearing a grey hooded top and grey tracksuit bottoms."
A 23-year-old Corby man has been arrested on suspicion of indecent exposure and has since been released under investigation.
Police are still appealing for witnesses to the incident to contact them and the spokesman urged anyone with information to call 101 or Crimestoppers anonymously on 0800 555111.