The Cork native has since recorded over 43 appearances, captaining the province at the beginning of the 2011/12 season.
His international career has seen him captain Ireland at both Schools and Under-20 levels, culminating in him winning his first full international cap against Italy in the 2012 RBS 6 Nations Championship.
A versatile forward, who has played across all of the back row positions, he has gone onto to win a further eight caps for his country and was recently named in the squad for the 2013 RBS 6 Nations Championship.
IRFU Chief Executive Philip Browne said: "Peter O'Mahony is one of the new generation of players that are continuing to emerge from the development pathways in Irish rugby.
"At this point in a young player's career, it is so important for both Munster and Irish rugby to be able to continue to have a positive input into that development.
"The policy for Irish rugby will be to continue to strive to keep all of our top players here in Ireland playing for our provincial teams."
Peter O'Mahony commented: "I am delighted to have my future sorted and to commit to Munster. It has been a really enjoyable journey so far for me in my career and the last two seasons in particular have been exciting, from breaking into the Munster team and captaining the side and then earning my first cap for Ireland.
"I'm thoroughly enjoying my rugby at the moment and feel there is much more that we can achieve with Munster and Ireland over the next couple of years and I wanted very much to be a part of that."
Munster head coach Rob Penney added: "We are delighted that Peter has agreed terms with the IRFU that keeps him here in Munster for the next two seasons. He represents the new breed of player, the next generation if you like, that are so critical to Irish rugby.
"To have him committing to the Munster organisation is a huge validation of what we are trying to achieve here. It is a particularly encouraging that a young man of such ability and talent has the belief that his ambition is best served by the structures that we have in place here.
"So, in that regard, this news is massive. It's great for Munster and for Ireland too."
Date of Birth: September 17, 1989
Height: 1.91m (6ft 3in)
Weight: 108kgs (17st)
Position: Back row
Club/Province: Cork Constitution/Munster
Munster Appearances: 43
Ireland Appearances: 9