The police received reports of the shooting near a square in southern Stockholm in the early evening, and found two people with gunshot wounds.
Another two were found injured nearby.
The teenager succumbed to his wounds while the others were taken to hospital.
“The person who died at the scene is a boy aged 15,” Stockholm police spokesman Towe Hagg told AFP.
Another 15-year-old boy was injured, as were a man and a woman aged between 45 and 65.
The police added that two men were arrested following a car chase south of Stockholm just under an hour after the shooting.
The police have launched an investigation into murder and attempted murder.
On Friday, another three people were injured in two separate shootings in the wider Stockholm area.
Sweden has struggled to rein in a surge of shootings and bombings in recent years, as gangs settle scores fuelled by the narcotics trade.
The country registered 391 shootings in 2022, 62 of them fatal, up from 45 in the previous year, according to police data.