The school's student body was 59.0% (347) White, 16.8% (99) Black, 12.4% (73) Hispanic, 7.3% (43) two or more races, 4.3% (25) Asian and 0.2% (1) Native Hawaiian / Pacific Islander.

Union Catholic offers many classes at a variety of levels that range from easy to difficult.

Accelerated and Honors courses are offered in English, History, Mathematics, World Languages and Science.

[15] The 1984 baseball team finished the season with a 20–3 record after winning the Non-Public Group A state championship, defeating Holy Spirit High School by a score of 8–1 in the tournament final.

[18] The 1987 team won the Parochial A state title after defeating McCorristin by a score of 45–42 in the championship game.

[19] The 1987 boys basketball team finished the season with a 25–2 record after winning the Non-Public Group A state championship with a 44–39 victory against runner-up Christian Brothers Academy in the playoff finals.

[20][19] The girls' volleyball team won the 2005 Non-Public state championship with a win over Lacordaire Academy in the tournament final (25-21, 19–25, 25–22).

[22][23] The boys' 4 × 200 m relay placed first with a time of 1:28.81 at the National Scholastic Indoor Championships in New York City, on March 16, 2008.

[24] The boys' 800m sprint medley relay team took first place at the Nike Outdoor National Championship held on June 18, 2008.

[32] The Union Catholic Performing Arts Company (UCPAC) showcases professional theatre on a high school level.

The company celebrated their 25th anniversary in 2006 with their fall comedy: and their spring musical: Sugar which is based on the 1959 film Some Like It Hot.

Some of their past musicals might include: Pippin, A Funny Thing Happened on the Way to the Forum, Honk!, and Seussical.

The 2008-2009 UCPAC Season presented the play Incorruptible by Michael Hollinger in the Fall and the musical Into the Woods by Stephen Sondheim in the spring.

The 17–18 season consisted of Peter and the Starcatcher for the fall play and The Mystery of Edwin Drood as the spring musical.

[citation needed] the 2021-22 year featured You Can't Take It with You (play) and Jesus Christ Superstar.