The University Interscholastic League was created by the University of Texas at Austin to provide educational extracurricular academic, athletic, and music contests. Bellaire choir students compete in two UIL contests per year: (1) Solo & Ensemble and (2) Concert & Sightreading.

The Solo & Ensemble contest, held in February, provides an opportunity for soloists and small ensembles to perform classical vocal literature before an adjudicator. All music must be chosen from a prescribed list and performed memorized. In addition to the numerous Bellaire soloists, the Madrigal Choir also competes annually in the madrigal division. Students and ensembles who perform a class I (highest level) piece and receive a superior rating qualify to perform at the state level in Austin at the end of May.

Concert & Sightreading is held at the beginning of April. This contest is for large groups performing classical choral literature. Two of the three required pieces must be chosen from a prescribed list. Each group must also sightread a piece of music before three adjudicators. Groups receive ratings for their stage performance as well as their sightreading. Superior ratings in both components result in a "Sweepstakes" trophy. Groups can also earn plaques if they receive superior ratings in one of the two components. Four Bellaire Choirs compete at Concert & Sightreading: Concert Chorale (varsity mixed); Chorale Women (varsity treble); Chorale Men (varsity tenor-bass); and Belle Ensemble (non-varsity treble).