[3][4] He was 13 when he won his first Irish schoolboys’ title[3][4] with his maiden international honours coming at the 2017 European Junior Championship where he took a silver medal.

[3][4] Only weeks after his 18th birthday, Clancy won his first Irish national elite title, defeating Patryk Adamus via split decision in the featherweight final in November 2019.

[3][4][6] After winning four fights in six days to reach the final at the 2021 European Under-22 Championships in Roseto degli Abruzzi, Italy, including beating number 3 seed Nenad Javanovic of Serbia, Clancy won gold when his opponent for the decider, Ahmad Shtiwi from Israel, failed to show-up due to injury therefore handing him the victory by walkover.

[3][4][7][8] Moving into senior international competition, he won a bronze medal in the light welterweight division at the 2023 European Games in Poland, losing to French world champion Sofiane Oumiha in the semi-finals.

[13][14] He was drawn to fight Obada Al-Kasbeh from Jordan in the first round on the opening day of the boxing tournament,[15] losing by 3-2 split decision despite his opponent being given a point deduction.