He is the only male dual player to win All-Ireland senior hurling and football medals in a single year.
Born and raised in Glanmire, County Cork, McCarthy first played Gaelic games to a high standard as a student at the North Monastery.
[3] Imokilly failed to retain their title, however, the divisional team reached the county final once again in 1986.
Cork avenged their defeat at minor level two years previously by beating Derry by 0–14 to 1–8.
Cork won on that occasion making it five-in-a-row of Munster titles, however, McCarthy was an un-used substitute.
Cork were "less than convincing" in that match and McCarthy was surprised on his return to Ireland to find that he was to make his championship debut in the All-Ireland final against Galway.
The second half saw Larry Tompkins kick six of his eight frees wide, resulting in a 1–14 to 0–11 defeat for Cork.
[8] During 1990, McCarthy was a member of the senior hurling team, but missed Cork's victory over Tipperary in the Munster final.
Two weeks after this victory, McCarthy was back in Croke Park playing in the All-Ireland football final.
[10] The Double was done and McCarthy "wrote himself into the storied pages of GAA history" by becoming the first (and, as of 2023, the only) player to win All-Ireland football and hurling medals in the same season.
The start of the year saw him collect a National Hurling League title following a three-game series with Wexford.
Despite this, McCarthy captured a fourth Munster football medal as Tipperary lost in the provincial final.
The game was yet another close encounter; however, a late goal won the day for Derry who secured a 1–14 to 2–8 victory.
In 1995, Cork defeated Kerry by 0–15 to 1–9, with McCarthy coming on as a substitute once again to collect his sixth and final Munster medal.
The All-Ireland semi-final was a similar situation to the previous year as eventual champions Dublin defeated Cork by 1–12 to 0–12.
He continued playing with the senior hurling team in 1996, however, Cork were defeated by Limerick for the first time in seventy-five years at Páirc Uí Chaoimh.
[citation needed] In late 2001 McCarthy took over as manager of the Sarsfield's senior hurling team.
Under McCarthy, Sarsfield's also won the East Cork championship in 2003 and the Munster club league in 2002.
Holland, McCarthy and the other selectors had refused to stand down, but County Board delegates voted for their dismissal to bring to an end the 97-day dispute.
[17] Once again he entered a dissatisfied camp as the Cork hurlers were unhappy about Gerald McCarthy's reappointment as manager.
Cork fielded a completely new team in the opening rounds of the National Hurling League before the selectors resigned along with Gerald McCarthy in March 2009.
[18] McCarthy also served as a selector, for two seasons, under Ger FitzGerald's management of the Cork under-21 hurling team.
[citation needed] McCarthy had some successes as manager of the Bandon intermediate hurling team.
[20] In October 2011 McCarthy was appointed manager of the Laois senior hurling team for a three-year term.
[21] His opening season with the team proved to be a trying one, with the county failing to pick up a single point from five games on their way to relegation from Division 1B of the National Hurling League.
They opened up their Leinster campaign with a win over Carlow before falling to Dublin by twenty-two points and then suffering a twenty-five-point deficit against Limerick in the All-Ireland qualifiers.
McCarthy tendered his resignation as manager of the Laois hurling team after just one season in charge, citing work commitments.