As the season continues and with his new provincial contract commencing in July 2014, O'Callaghan is in line to surpass fellow Cork man Ronan O'Gara's all-time leading tally of 240 Munster appearances.
On the international front O'Callaghan has made 94 appearances for his country and is currently involved with the Ireland squad as they prepare for the GUINNESS Series.
The 34-year-old who made his Munster debut back in August 1998 against Edinburgh Reivers is more than happy to cement his future with Munster Rugby.
"I love playing for this team and representing my home province and supporters each week," admitted O'Callaghan.
"Running out for Munster is something I've always wanted and I've been fortunate to make my career out of it, and to continue doing so for the next few years is just what I want. The main thing for me is that I still enjoy it and I have the opportunity to do it."
Munster head coach Rob Penney commented: "We are lucky to have someone of Donncha's calibre and experience commit his future to Munster Rugby.
"He is great with the younger lads and drives everyone on. His own dedication and work ethic are an example to all and it's good to know he is on board for another two seasons."