Humberside Police were called to the property on Beverley Road on Tuesday afternoon following a call at around 3pm.
Officers who attended found a man's body at the scene and detectives are now investigating.
Detective Chief Inspector Phil Gadd said: “Officers have been in attendance at a property on Beverley Road in Hull this afternoon Tuesday 28 May following a call at around 3pm.
“Upon arrival a man’s body was discovered inside an address. An investigation was launched to identify him and establish the circumstances surrounding his death.
“Our priority first and foremost was to identify this person and also to inform his family which we have now done.
“They are being supported by our specialist officers at this time."
Anybody with any information in connection with the man's death can contact police on the non-emergency number of 101 quoting log 331 of 28/05/19.