Gillian has spent more than ten-years in the sport of cycling as a professional and amateur cyclist and more recently as a coach and manager. In 2015, Ellsay was the U23 Canadian national time trial champion. She represented Canada at the world championships on the road and track. Her success earned her contracts with pro teams Colavita-Bianchi, Rally Cycling, and Instafund Pro Cycling. She worked with the likes of Gord Fraser, Ina-Yoko Teutenberg, and Richard Wooles.

She retired in the spring of 2022 and started coaching and managing the TaG Cycling Race Team. She hopes to continue to learn and grow as a Sports Director with Cynisca Cycling.