Police would like to speak to the owner of the dog.
The incident took place in Spencer Gardens on May 6 at about 3pm.
A medium sized, brown dog was off the lead when it jumped up and bit a man, causing a minor injury.
The owner managed to get the dog onto its lead and spoke with the other man. A short time later, he came back into the park without the dog to apologise. However, no names or details were exchanged.
Police would like to speak to the owner of the dog, who was white and wearing a blue t-shirt, and are asking him to get in touch.
Witnesses to the incident, or anyone with any information, are asked to call Northamptonshire Police on 101, quoting reference number 17000208138.