Steven Dickie, 24, was convicted earlier this year over the killing of Steven Donaldson, whose body was discovered in a car park at Kinnordy Nature Reserve near Kirriemuir, Angus, on June 7 last year.
The Scottish Prison Service (SPS) confirmed on Friday that Dickie had died at HMP Perth.
The SPS said police have been informed and a fatal accident inquiry will be held.
Dickie and co-accused Callum Davidson were convicted in May of murdering Mr Donaldson following a trial at the High Court in Edinburgh and jailed for life.
Dickie was sentenced to a minimum of 23 years behind bars, while Davidson was told he must spend at least 24 years in jail.
Mr Donaldson’s former girlfriend Tasmin Glass, 20, was jailed for 10 years after being convicted of culpable homicide.
The court heard Mr Donaldson, 27, from Arbroath, had been lured to his death and was subjected to a “sustained and prolonged” attack involving extreme levels of violence.
Dickie and Davidson attacked Mr Donaldson after he had arranged to meet Glass, believing they would be meeting to discuss their relationship.
Mr Donaldson was initially attacked at the Peter Pan children’s play park at Kirriemuir, before he was transported to the nature reserve.
There, he was hit again on the head and body with a knife and a baseball bat and was repeatedly struck on the neck with a heavy, bladed weapon before his car was set on fire.
An SPS spokesman said: “Steven Alexander Dickie, 24, a prisoner at HMP Perth, has died.
“He was convicted at Edinburgh Court on May 30, 2019. Police Scotland have been advised and the matter reported to the procurator fiscal.
“A fatal accident inquiry will be held in due course.”