High School (Fossil Ridge)
Coleen Gillilan was part of a legendary group of girls during her time at Fossil Ridge. At the state meet her junior year, she was part of the squad that won 10 of the 12 events and scored the most points in Colorado state history. Gillilan added wins in the 200 free and 100 fly to that tally, and was on the winning 200 medley relay (broke the national high school record) and 200 free relay (broke the state record).
On March 13, 2018, Gillilan announced her verbal commitment to swim for the University of Notre Dame.
College (Notre Dame)
Gillilan was the bronze medalist in the 200 fly (1:54.79) and finished 6th in the 200 IM (1:57.29) and 8th in the 100 fly (52.86) at the ACC Championships in Greensboro, South Carolina. She also swam on the Irish’s 4th place 800 free relay, 6th place 200 medley relay and 400 medley relay and 7th place 200 free relay at the ACC meet.