Extensive scientific research has shown that Lucozade Sport hydrates and fuels the body better than water and increases endurance capacity and delays fatigue.
Under the new agreement, Lucozade Sport will provide financial and product support to the IRFU, as well as access to nutritional and sports science advice for management and players.
The IRFU will also be provided with Lucozade Sport's new range, Lucozade Sport Elite, for the first time, in advance of the upcoming RBS 6 Nations Championship, which will be of great benefit to Declan Kidney and the Ireland squad in their preparations for the tournament.
"As the only healthcare company in the sports drink market, we are fully committed not alone to providing athletes at all levels with the best products possible, but also to ensuring that those involved in sport have the best possible nutritional and scientific information available to them.
"We take our commitment to rugby, and to sport in general, very seriously.
"Our scientific knowledge is the result of years of research and allows us to help sporting organisations here in Ireland support their athletes in training, match preparation and recovery, as rehydration and recovery products is an essential part of any athletes training."
Padraig Power, IRFU Commercial and Marketing Director, said: "We are delighted to announce this partnership with Lucozade Sport. The brand has been an outstanding supporter of rugby over many years and we look forward to working with them closely over the coming seasons."