The 23-year-old was arrested on suspicion of murder.
He is the fourth person to be arrested in relation to the death of the teenager, who was stabbed to death in the Warnford Walk area of Merry Hill on Monday.
The 16-year-old was found with stab injuries at around 4.30pm on Monday afternoon. Officers who attended the scene gave CPR before the victim was treated by paramedics,
Despite the work of ambulance staff, the teenager was declared dead at the scene.
On Tuesday morning, three men were arrested - two, both aged 22 on suspicion of murder and one, aged 39, on suspicion of assisting an offender.
An air ambulance was seen landing on a field near to Fareham Crescent in the Merry Hill area of the city on Monday evening.
West Midlands Police have said that they have stepped up patrols in the area and that anyone with concerns can stop and talk to them if they need reassurance or advice.
The four men all remain in custody as inquiries continue.
Anyone with information should contact police via 101, or on Live Chat on the website, quoting log 3421 of 18 September. Or to remain anonymous speak to Crimestoppers on 0800 555 111.