Murphy, 32, was the lone survivor from the Offaly team defeated by Kilkenny in the 2000 All-Ireland final.
“I’ve given the matter a lot of thought over the last few months, but I’ve finally decided the time has come for me to finish playing with Offaly,” said Murphy.
“I’ve informed (Offaly manager) Ollie Baker of my decision and he fully understands my reason for taking it. The demands of the modern game are increasing all the time for inter-county hurlers. In fact, between group training and doing work on your own you need to be involved for four to five nights each week to keep up to Championship pace. And if you’re not in a position to give that kind of commitment, you’re not being fair to either your teammates or yourself.”
Murphy will continue to play with his club, Ballyskanagh.
Along with the 2000 All-Ireland final defeat, Murphy figured on the losing end in the Leinster final of the same year – also against the Cats – and in the 2004 provincial decider against Wexford.
“I’ve plenty of regrets about my time with Offaly,” admitted Murphy as he looked back on his senior inter-county career which commenced at 19.
“When you get to play in an All-Ireland senior final at such a young age, you think you’re going to be there every year. Lads like Brian Whelahan, Joe Dooley and John Troy were coming to the end of their careers when I first came on to the team. But the future still looked bright for the county as Offaly won the Leinster U-21 and minor titles in 2000. But as we know only too well Kilkenny went on to dominate Leinster hurling since 2000.”