Ireland’s new jersey will be unveiled next Monday after the FAI confirmed Castore as the kit supplier until 2028.
The English sportswear manufacturer was widely expected to take over from Umbro, ahead of the Euro 2024 qualifiers.
FAI chief executive Jonathan Hill today said the contract was a ‘significant commercial deal’, but did not disclose how much it is worth to the association.
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Ireland fans will be able to pre-order the new home kit from www.shop.irelandfootball.ie from March 20.
News of the Castore deal follows hot on the heels from last week’s reveal of a new Ireland crest and separate FAI logo.
Ireland are the first international football team that Castore have teamed up with since they were founded in 2015.
Castore produce kits for a number of club sides including Newcastle United, Aston Villa, Wolves, Preston North End, Rangers, Sevilla and Bayer Leverkusen.
They are also prominent in cricket, Formula 1 and cycling circles.
Hill said in a statement: “This is an exciting time as we announce a new kit partner, a new shirt and a new crest for our international teams.
"In Castore we believe we have found an ambitious and forward-looking partner who share our desire to move forward confidently and positively into a new era for the FAI and Irish football."
Hill continued “This is a significant commercial deal for the association which helps us in our core strategic objective of creating a more stable financial base for the business and for the game as a whole.”
Castore Founder Tom Beahon said: "We are extraordinarily proud that Castore will have the honour of producing the iconic Ireland jersey until 2028.
“We fully understand the responsibility we have to carry on that tradition and history.”
Beahan continued: “Along with our financial commitment to the FAI, we will invest significantly into the FAI’s e-commerce infrastructure.
“(We will) provide a best-in-class online shop for Ireland fans home and abroad and will align with the FAI’s strategic ambition to embrace digital technologies to better connect with all fans.”