The victim was found with stab wounds near Short Heath Park in Erdington on Monday night.
Emergency services attended the scene at the junction of Beech Road and Sycamore Road at around 8pm.
He was taken to hospital with serious injuries where he remained overnight in a stable condition.
West Midlands Police said a 15-year-old boy was arrested during the early hours of Tuesday on suspicion of attempted murder.
He remains in police custody.
Det Sgt Simon Hanlon, from force CID, said: “This is a shocking attack on a young boy who has sustained serious injuries.
“We know a number of people were involved and that the attack may have taken place in a nearby park.
“I am urging anyone with any information to contact us as soon as possible.”
Anyone with information can call police on 101.
The stabbing happened just yards away from Goosemoor Lane where 20-year-old James Teer died when he was shot in a drive-by on August 8 this year.