Billy Bluejay is the official mascot of the Creighton University Athletics Department. The Bluejays were originally depicted by a birdwatcher's bluejay, but that was changed in 1941 when Joseph P.Murphy, a Creighton Alumnus, designed the current version of Billy, one with a more human stance and expression.

Prior to 1924, Creighton teams were referred to as the 'Hilltoppers', but that name lost favor because at least six other teams in the country also used the same nickname. The Omaha Bee assisted the University's Athletic Board and Alumni Association in finding a new nickname by asking readers to submit possibilities. After reviewing 200 entries, the Athletic Board decided upon 'Bluejays' because of the school's colors, Blue and White.

Today, Creighton remains the only NCAA Division I Athletics program known officially as the Bluejays.