Saint John Mary International School.

Which direction it is from Ayutthaya

Ayutthaya’s defining schooling problem is not distance, it is direction. Guides written from Bangkok outwards assume the only road out is south. It is not.

EAST, not south. The campus sits on Phahonyothin Road in Mueang Saraburi -- the same trunk road that runs up through the Wang Noi side of Ayutthaya province, which is why the eastern edge of Ayutthaya is the part of the province that makes this school work. Ayutthaya families have been sent 80km south to Bangkok by every guide including ours; this is a comparable run in the opposite direction into a far cheaper market.

Where this school stops

Grade 12, around age 18 -- and, unlike the post-16 provision found in Pattaya, Koh Samui and Krabi, there is no indication anywhere on the school's site that the final years are blended, hybrid or studied remotely. The Middle and High School sit under one on-campus heading.

What a leaver actually holds

The curriculum label and the leaving qualification are different things. For a family that may move country again, this line is the decision — and a blank cell is itself a finding.

A US high school diploma on the State of California curriculum, with Advanced Placement available for college credit. The school additionally hosts SAT and TOEFL iBT as a certified test centre, so a leaver can sit the American university-entry sequence without leaving the campus.

Where the campus actually is

131 Moo 1, Phahonyothin Road, Nong Yao, Mueang Saraburi 18000

On Phahonyothin Road, the north-south trunk route, in Mueang Saraburi. Measure the door-to-door drive yourself at 07:00 on a weekday rather than trusting a map estimate -- that is the standing rule across this rotation and it has never once been generous to the school.

School van — published routes

The school publishes a School Van Routes & Fees page, with the actual routes issued as a downloadable PDF (last updated for the 2025-2026 year). We are NOT asserting that a van route reaches Ayutthaya -- we could not read the route list -- and that is precisely the question to put to the school first, because the answer decides whether this is a day school or a boarding school for your family.

Ayutthaya area guides families use for this school run: Wang Noi & the Industrial Corridor · Bang Pa-in & the Riverside East Corridor

The curriculum pathway, stage by stage

• Kindergarten division.
• Elementary.
• Middle and High School, taught on campus.
• Advanced Placement offered as a named programme with its own page, and the school is a College Board AP test centre in its own right.

Accreditations, authorisations & affiliations

Three different claims, routinely collapsed into one. A whole-school accreditation (WASC, CIS, NEASC, Cognia) assesses the school itself. An examination-board authorisation (College Board, Cambridge, IB) means it may enter pupils for those exams. A membership or affiliation is neither. And “none named” is a fourth state, distinct from “not accredited”.

• ACCREDITED: fully accredited by the Western Association of Schools and Colleges (ACS WASC) -- stated in words and displayed as a badge on the school's own accreditation page.
• RECOGNISED: recognised by the Thai Ministry of Education as an institution of international status offering Pre-kindergarten through Grade 12.
• AFFILIATIONS (not accreditation): ONESQA, the International Schools Association of Thailand (ISAT), ISAA, and Optimus Education.
• TEST CENTRE AUTHORISATIONS (not accreditation): College Board Advanced Placement, SAT, TOEFL iBT and the HSK Chinese proficiency test.

Religious character

The school states it is recognised as serving students of various races and religions, and its published mission is built on integrity and service to others rather than a doctrinal statement. It publishes no statement of faith and no compulsory religious studies requirement that we could find.

Boarding

For an Ayutthaya family this is not a lifestyle question, it is the question. Without boarding or a van route, a Saraburi school is a daily drive across a provincial boundary.

Yes -- and this is the fact that makes the school reachable from Ayutthaya at all. SJMIS runs boarding as a named part of the school with its own section, dormitories, weekend and monthly activity programmes. Read the wording carefully before committing: the school describes supervision by "dorm deans OR homestay parents", which means the boarding offer covers at least two materially different arrangements. Ask which one your child would actually be in, where it physically is, and who is responsible overnight.

Who it suits

An Ayutthaya family that needs a genuine international education with an American exit route and can either drive the Phahonyothin corridor east or board weekly. It is the most complete international option within reach of Ayutthaya that is not in Bangkok, and by a wide margin the most affordable one with full WASC accreditation.

What we could not verify — and where sources disagree

We publish these openly rather than smoothing them over. A school guide that hides its uncertainty is not much use to a family making a decision this big.

• The van route PDF is the single highest-value unknown on this page. If a route reaches the Wang Noi or Bang Pa-in side of Ayutthaya, SJMIS becomes a day-school option for a large part of the province. If it does not, it is a boarding decision. Ask before anything else.
• The boarding description offers "dorm deans or homestay parents" in one sentence. Dormitory boarding and homestay placement are not the same product -- this is the same distinction that caused a directory to record Udon Thani's UDIS as having boarding when what it has is a homestay partner. Confirm which one is on offer for your child's year group.
• The accreditation page's own last-modified date is February 2023. The WASC accreditation is displayed as current and stated in prose, but accreditation runs in terms -- ask for the current term's end date rather than reading the badge as open-ended.
• Reported enrolment of around 450 comes from directory records, not from the school, and the school publishes no roll figure we could find.
• The school's own footer carries a placeholder string where a Facebook URL should be, and its Chinese-language flag links to a PDF brochure while the Korean flag links to an external blog. Cosmetic, but a sign the site is loosely maintained -- do not treat an undated page on it as necessarily current.
• SJMIS is owned and operated by Sang Young Mary Company, founded by the late Ajarn Samai Chinapha. Ownership is published and clear, which is more than several schools in this rotation manage, but it is a single-company school rather than part of an international group.

Ask every school in the Ayutthaya catchment this

• Before you accept a Bangkok commute, price the eastern option. Saraburi has four international schools at a broadly comparable radius from Ayutthaya, three of which board, at published fees in the low hundreds of thousands rather than Bangkok's four hundred thousand to over a million. Every guide sends you south; check east before you sign a lease.
• Ask Saint John Mary for the current school van route list, in writing. Whether a route reaches the Wang Noi or Bang Pa-in side of Ayutthaya is the single fact that decides whether the strongest international school within reach is a day school or a boarding school for you.
• When a school says boarding, ask whether it means a dormitory on campus or a homestay placement with a partner family. They are different products with different supervision, and directories record both as "boarding: yes".
• Ask what qualification a leaver actually holds, and who awards it. Three of the four Saraburi schools run American programmes and only one of them also hosts the College Board, SAT and TOEFL testing on site. One names no leaving qualification at all.
• Ask whether the final years are taught on campus or partly online. One of the four is built around blended learning by design and says so; that is a feature for some families and a deal-breaker for others.
• For any Thai school's English Program, ask how many periods a week are genuinely delivered in English, and what a non-Thai-speaking child faces at admission. Cost is not access: Thai EP and state-school entry usually runs through an examination sat in Thai on a fixed national timetable.
• Before shortlisting any school you found in an English-language listicle, apply the four-part existence test: does it have its own domain, a findable street address, a phone that answers, and does its own homepage carry any closure or rebranding notice? The most syndicated page on Ayutthaya schooling currently recommends a school that does not exist.

Sources & References

• Ministry of Education, Thailand

Primary and official sources are cited above. Government rules, fees and procedures in Thailand change over time and vary by office; always confirm current requirements with the relevant authority before relying on them. BAANLYY never takes paid placement in editorial content.