He was taken to hospital with serious injuries after police were called to reports of a stabbing just before 11pm.
Police believe a group of young people were gathering in Nuttall Park on Saturday evening when the teen was assaulted.
The incident happened on July 8 but police have released details of the appeal today.
Officers are keen to speak with anyone who may have been in the area and are particularly keen to speak with a white male, of a slim build who was around 5ft 11in tall and wearing a dark North Face jacket.
He is believed to have information to assist lines of enquiries.
A Greater Manchester Police spokesperson said: “Police appeal for information after stabbing in Nuttall Park, Ramsbottom.
“At 10.57pm on Saturday 8 July, police were called to reports of a stabbing in Nuttall Park, Ramsbottom.
“Emergency services attended and a male in his teens was taken to hospital with serious injuries and subsequently released.
“Police believe a group of young people were gathering in Nuttall Park on Saturday evening when the teen was assaulted.
“Officers are keen to speak with anyone who may have been in the area before, during, or after the incident.
“If you have any information – or any CCTV, mobile, dashcam or doorbell footage – please report it directly to GMP.
“Office are particularly keen to speak with a white male, of a slim build, 5ft 11in tall and wearing a dark North Face jacket who is believed to have information to assist lines of enquiries.
“Information can be shared with GMP by calling 0161 856 8112 quoting log 4055 of the 08/07/23 or by using our Live Chat function on our website https://orlo.uk/9WeaZ
“Alternatively, information can be shared anonymously via the independent charity Crimestoppers by calling 0800 555 111.
“We all have a part to play in fighting, preventing and reducing knife crime. If you know or suspect someone is carrying a knife, please report it immediately – before it is too late. You can contact GMP via https://orlo.uk/yxRqt or 101.”