'SJ23' is accredited by/a member of the Roman Catholic Archdiocese of Galveston-Houston (RCAGH), led by Archbishop Daniel DiNardo.

[citation needed] The Houston real estate company Westside Ventures Inc. donated the land used for the school, which first opened in the fall of 2004; the initial construction had a cost of $8 million and included classroom and athletic facilities.

[2] It was the first Catholic school to be built in Greater Houston since Strake Jesuit College Preparatory opened in the 1960s.

The school held its 10h anniversary celebration on October 11, 2013, and the canonization of Pope John XIII was expected the following year.

Students from the Katy, Spring Branch, Cypress, Memorial, Rosenberg and Sugar Land areas attend the school.

These houses are Aquinas, Borromeo, Lisieux, Loreto, and Neri, each named after an important saint of the Catholic church.

Saint John XXIII High School is located on a 35-acre (140,000 m2) parcel of land at the intersection of the Grand Parkway and Franz Road.

[2] Initially a smaller gymnasium with attached locker rooms served the school's athletic needs.

The school offers 15 different athletic teams, including football, volleyball, boys' and girls' basketball, baseball, softball, swimming, tennis, boys' and girls' soccer, cross country, track and field, golf, lacrosse (offered by an offcampus club) dance/drill team, and cheerleading.