In 2003, he was part of the Laois team that won the Leinster Senior Football Championship title for the first time since 1946.
In 2003, Munnelly starred when his club Arles–Kilcruise won the Laois Senior Football Championship title.
In 2005, he captained Laois to the final of that year's Leinster Senior Football Championship; they were beaten by Dublin.
As of the conclusion of the 2022 season, Munnelly was the joint longest serving inter-county player (alongside Niall McNamee of Offaly).
In 2005, Munnelly was chosen to represent Ireland in the International Rules Series away to Australia, and in 2006 he was nominated for an All Stars Award.