So, to celebrate St Patrick’s Day, we took a look at 12 of the best Irish players to have shone at Bramall Lane. Is your favourite on the list?
1. Alan Kelly, 1992-1999
Kelly won 34 caps for the Republic of Ireland. He was a member of Eire's 1994 and 2002 World Cup squads, but was the team's second-choice goalkeeper on both occasions and didn't play a game in either tournament.
Photo: Mark Thompson
2. David McGoldrick, 2018 to present
McGoldrick won 12 caps for the Republic, scoring his first goal for his country in September 2019 - the equaliser in a 1-1 draw with Switzerland at the Aviva Stadium in a UEFA Euro 2020 qualifying match. He retired from international duty last year
Photo: Stephen Pond
3. Paul McGrath, 1997-98
Considered by many to be the Republic's finest ever footballer, McGrath was over the peak of his powers when he arrived at United in the late '90s but he oozed class, despite only playing a handful of games in United colours
Photo: Paul Chappells
4. Billy Gillespie, 1912-1933
Gillespie was United's captain when the club won the FA Cup in 1925. The striker scored 137 goals in 472 matches. He was a part of the Ireland side that won the 1914 British Home Championship outright. Gillespie played for the Ireland national team operated by the Irish Football Association (IFA), which now operates the Northern Ireland national football team. Gillespie held the IFA record for most international goals scored for 78 years, with 13 goals. His record was equalled by Colin Clarke in 1992 and broken by David Healy in 2004.
Photo: Chris Holt