Keith Lee, who was facing charges in relation to the murder of his estranged wife Joanne Lee, has been found dead in his prison cell on Thursday morning.
The body of Ms Lee, also known as Joanne Ball, was found in a wardrobe in a house in Ranelagh in February.
A spokesman for the Prison Service confirmed an inmate had died overnight in Mountjoy Prison.
Foul play is not suspected in relation to the death. It is understood that prison officers believe Mr Lee may have died by suicide.
Mr Lee was charged on March 18th in relation to the murder of his wife.
Her body was found wrapped in a sleeping bag in a wardrobe in a flat in the Dublin suburb of Ranelagh.
A postmortem found she had been strangled.
Mr Lee had been in the apartment when gardaí called after she was reported missing.
However, he jumped from the third floor apartment window on Ranelagh Road and suffered serious injuries, including broken legs, when he hit the ground.
He then self harmed with a box-cutter knife. One of the gardaí who had called to the property took off some of his own clothing and fashioned a tourniquet to stem the bleeding.
He was then taken by ambulance to St Vincent’s Hospital. He appeared in court last month in a wheelchair.
Gardaí searched the apartment and found Ms Lee’s body in the wardrobe. She had been dead for at least 48 hours.