He made his first-class debut in 2015, and plays for the Ireland cricket team, and previously the English side Durham.
[14][15] In May 2019, in the opening match of the 2019 Ireland Tri-Nation Series against the West Indies, McCarthy took his 50th wicket in ODI cricket.
[16] In October 2019, he was added to Ireland's squad ahead of the playoff matches in the 2019 ICC T20 World Cup Qualifier tournament in the United Arab Emirates, replacing David Delany, who was ruled out due to an injury.
[20] McCarthy was named in Ireland's Test squad for their tours of Bangladesh in March 2023 and Sri Lanka in April 2023.
[21] In 2023 McCarthy registered his maiden T20I half-century with a score of 51* off 33 balls against India in a rain-affected T20I encounter at Malahide.