Catholic Boy is a bay horse with a white star bred in Kentucky by Fred W. Hertrich III & John D. Fielding.

[4] Catholic Boy made his track debut in a maiden race over seven and a half furlongs on turf at Gulfstream Park on July 20, 2017.

[6] In the Grade I Breeders' Cup Juvenile Turf at Del Mar Racetrack on November 3 Catholic Boy finished fourth behind Mendelssohn, Untamed Domain and Voting Control with Masar and Sands of Mali among those running unplaced.

With Franco in the saddle he tracked the leaders before moving up to take the lead on the final turn and drawing away to win by four and three quarter lengths from the favourite Avery Island.

[7] On his three-year-old debut Catholic Boy started odds-on favourite for the Grade III Sam F. Davis Stakes on dirt at Tampa Bay Downs in February but was beaten half a length by the Mark Casse-trained Flameaway.

Irad Ortiz took over the ride from Franco when the colt contested the Grade I Florida Derby at Gulfstream on March 31 and came home fourth of the nine runners, twelve lengths behind the winner Audible.

Ridden by Javier Castellano he led soon after the start and after being headed by the favourite in the stretch he rallied to regain the advantage and won by a neck.

After tracking the front-running Mendelssohn Catholic Boy went to the front inside the last quarter mile and drew away in the final furlong to win "readily" by four lengths.

"[13] For his final run of 2018, Catholic Boy was matched against older horses in the Breeders' Cup Classic at Churchill Downs on November 2.

He settled in second place behind Real Story before taking the lead a furlong out and held off the late challenge of Admission Office to win by half a length.

[16] On 6 July the colt started favourite for the Suburban Handicap over ten furlongs on dirt and finished second to the six-year-old Preservationist, to whom he was conceding six pounds in weight.