Speaking to the Limerick Leader minutes after the announcement, Hugh Murray said he was delighted to accept the award "as an architect, a Limerick man and a Munster supporter".
The firm has created a landmark for Limerick and Mr Murray said the firm is "really pleased that the project is getting the recognition that it deserves".
Building work on Thomond Park commenced in early March 2007 and the stadium took 20 months to construct in a makeover that cost €40 million.
The awards will be hosted by RTE broadcaster Ryan Tubridy in The Cow Shed Theatre Farmleigh tonight.
Murray O'Laoire Architects are also up for an award in the best healthcare building category for Tullamore Hospital, and Thomond Park could also win in the best sports building category.
The Limerick architects might leave Dublin weighed down with awards tonight. "We hope so, we're up to carry them," he laughed.