Kieran is a Ronkonkoma, New York native where he attended Connetquot High School. While playing at St John’s University, McArdle was a 3x All-American and a 2x BIG EAST Player of the Year. Kieran went on to play for the Atlas LC during the PLL’s first ever season. He was subsequently selected seventh overall by Waterdogs LC in the 2020 Expansion Draft. In the 2022 PLL season Kieran was second amongst all players in points and led the league in assists. Kieran was selected as a 1st Team All Pro Attackman along with leading the Waterdogs to a PLL Championship.