Ona Halladay took over the role of Director of Athletics in the fall of 2019, after previously serving as Associate Director of Athletics and Assistant Director of Athletics in her tenure at D'Youville. Halladay also serves on D'Youville's President's Council.

During her short time at the head of the department, Halladay has been instrumental in the 2020 rebranding of D'Youville Athletics from the Spartans to the Saints, as well as the athletic department's move from NCAA Division III to Division II and admittance into the East Coast Conference.

Halladay joined the D’Youville staff in August 2013, spending seven seasons as D’Youville's head softball coach in addition to roles such as senior women's administrator and compliance director.

Throughout her time at D'Youville, Halladay has assisted with the budget and finances for the department, has handled NCAA rules enforcement, and has worked with all coaches and department members in various ways.

Entering into the coaching ranks in 2010, Halladay joined the staff at St. Bonaventure where she was an assistant coach under long-time SBU head coach Mike Threehouse. Under Halladay’s direction, players were named to the Atlantic 10 All-Rookie Team and the Atlantic 10 All-Conference Team, and the team's home run total was ranked 17th in the country during the 2011 season. With instruction from Halladay on her hitting techniques, St. Bonaventure player Ashley Snider was able to break the SBU career home run record.

A 2010 graduate of SUNY Brockport with a bachelor of science in psychology, Halladay was a two-time All-SUNYAC softball selection as a member of the Golden Eagles. The native of Palmyra, New York began her collegiate career playing at St. John’s University for two seasons where she was a two-year letterwinner.

Halladay graduated from Canisius College in 2018 with her master's in sport administration.