Emergency services were called to the Denaby Main area of the town around 2.30pm on Wednesday after reports that an 18-year-old man had been attacked.
Police went to flats off Wadworth Street and the victim was taken to hospital where he was pronounced dead.
South Yorkshire Police said his family have been informed.
A force spokesman said: “An 18-year-old woman has been arrested on suspicion of murder and is currently in police custody.
“An investigation is under way and officers are in the local community making enquiries.”
Police have asked anyone with information to call 101.