Officers were called by the ambulance service to attend a property in Chipperfield Drive at around 20.20 GMT on Friday, after a 22-year-old man was seriously injured.
He was taken to hospital but died in the early hours of today.
A forensic post-mortem examination will now be carried out to determine the cause of death.
His next of kin have been located and informed, and they’ll be fully supported by specially trained liaison officers.
A 23-year-old woman has been arrested in connection with this incident and remains in custody.
Senior Investigating Officer DI Ben Lavender said: “This is a devastating incident in which a man has lost his life and a thorough investigation will now be carried out to establish what happened.
“An arrest has been made and we can confirm the victim and the person arrested were known to each other.
“There’ll be a continuing police presence at the scene of this incident while our enquiries continue. We’ll also be increasing patrols in the area to support and reassure the local community, with neighbourhood officers able to answer any worries or concerns.”
If anyone has information that would assist the investigation, please call Avon & Somerset Police on 101 and give the call handler the reference number 5222071378.