How to Apply to St. John XXIII College Preparatory (SJ23)

St. John XXIII College Preparatory (SJ23) is a private, coed Catholic high school in Katy, Texas, serving grades 9–12. To apply, start on the school's Admissions section, which contains dedicated How to Apply, Important Dates, and Visit SJ23 pages. The site does not publish the full step-by-step application checklist or specific deadlines in the material available here, so the practical path is to use those three pages as your source of truth and confirm details directly with the admissions office.

Where the application information lives

The school's navigation lists these admissions-related pages:

If you are applying as an international student, use the International Student Program page rather than the general admissions flow, since requirements can differ.

A practical sequence

1. Review How to Apply. Read the full list of required steps and materials before starting anything, so you don't submit items out of order.
2. Check Important Dates. Note every deadline that applies to your entry year. Dates are listed on the site rather than fixed here, and they can change by admissions cycle.
3. Schedule a visit through Visit SJ23. A campus visit lets you confirm fit and get questions answered in person. The site also offers a "Visit Us!" prompt on the homepage.
4. Review Tuition & Financial Aid. Understand cost and aid options before or alongside applying, since aid processes often run on their own timeline.
5. Submit and track. Follow the instructions on How to Apply for submission, and use the site's Login option if the school provides an applicant portal.

What to know before you start

• Grade range: SJ23 enrolls grades 9–12 only, so it is a high school application, not a K–12 one.
• Mission fit matters. The school describes itself as forming students "in mind and heart" in a Christ-centered Catholic community focused on academic excellence, virtue, and service. Expect the process to weigh more than test scores.
• Scale and selectivity context: roughly 1,200+ alumni, a 13:1 student-to-faculty ratio, 144 course offerings, and 100% college acceptance for the class of '24. These figures describe the school, not admissions odds.
• Scholarships exist but aren't automatic. The site reports $11M+ in scholarships awarded to the class of '24. That figure does not tell you who qualifies or how to apply—check Tuition & Financial Aid for the actual process.

Common sticking points

• Assuming deadlines are fixed year to year. Always re-check Important Dates for your specific entry year.
• Skipping the visit. Visiting is listed as its own admissions step, and it's the fastest way to resolve questions the website doesn't answer.
• Confusing admissions with other portals. The site has separate logins and stores for athletics, events, and the school store; those are not the application system.
• International applicants using the domestic flow. Use the International Student Program page instead.

The bottom line

Apply by working through the Admissions section in order: How to Apply for requirements, Important Dates for deadlines, Visit SJ23 to see the campus, and Tuition & Financial Aid to plan costs. Because the site does not publish the full checklist or specific dates in the material available, treat the school's own pages and admissions office as the authoritative source before you commit to a timeline.