Wayne O'Donoghue has been found not guilty of murder but guilty of the manslaughter of 11-year-old Robert Holohan.
The jury at the Central Criminal Court, sitting in Cork, deliberated for four hours and 21 minutes before reaching a verdict.
O'Donoghue will be sentenced on 24 January.
O'Donoghue, an engineering student, had admitted killing his neighbour in January of this year.
Robert's body was found on 12 January near Inch Strand in east Cork, about 19km from his Ballyedmond home. He had been missing since 4 January.
21-year-old O’Donoghue was arrested on 17 January. He was originally charged with manslaughter but this was later replaced with a charge of murder.
