The boy remains in police custody over the three alleged armed robberies, which took place in the Woodseats and Meersbrook areas of the city on Tuesday, December 6.
At around 6pm, a 22-year-old man was walking along Holmhirst Road, Woodseats, when he was approached by a man said to have been carrying a knife reportedly made demands for cash.
An hour later, at around 7pm, a 31-year-old woman on Rushdale Road, Meersbrook, reported being approached by a man believed to be armed with a knife who demanded cash before making off.
At around 7.05pm a third incident was reported to police by a 39-year-old woman, who stated whilst on Woodbank Crescent, Woodseats, a man armed with what is thought to have been a bottle demanded cash.
Quantities of cash were stolen in each of the incidents.
No was hurt in the incidents, however the man and two women have been left incredibly shaken by what has happened.
The man has been descried as mixed race, of a slim build, around 5ft 10ins tall and wearing a dark coloured puffer style jacket with the hood up, dark coloured trousers and carrying a rucksack.
Detective Chief Inspector Paul Wilson who is leading the investigation into the incidents has said: “At this time all of the incidents are being treated as linked and an investigation has been launched to determine the exact circumstances.
“I understand incidents such as this will cause alarm amongst our communities, however I would like to offer my reassurance that violence such as this will not be tolerated.
“Our priority is the safety if everyone in South Yorkshire and if anyone has any information about the incidents that may be able to assist with our enquiries, please report it via 101 quoting incident numbers 984, 875 or 98 of 5 December. Anonymous information can also be given to Crimestoppers on 0800 555 111.”