If you want an IB education for your children near Cascais or Lisbon, you have more choice than you might expect. But “IB school” can mean very different things. Some schools teach the IB from age 3. Others teach their own curriculum and only switch to the IB Diploma for the last two years. A few are still waiting for authorisation.
This page answers the questions parents ask most: which schools offer which IB programmes, from what age, what they cost, and what results they publish.
We checked every IB status against the official IB school finder, and everything else against each school’s own website.
Last checked: 21 October 2026.
The four IB programmes in one minute
The International Baccalaureate (IB) has four programmes. A school has to be authorised by the IB for each one separately.
- Primary Years Programme (PYP): roughly ages 3 to 12.
- Middle Years Programme (MYP): roughly ages 11 to 16.
- Diploma Programme (DP): the last two years of school, ages 16 to 19. This is the “IB” most universities know.
- Career-related Programme (CP): also ages 16 to 19. It combines some Diploma courses with career-related study.
IB schools near Cascais and Lisbon at a glance
These are the authorised IB schools in our Cascais schools guide. “Yes” means the IB lists the school as authorised for that programme.
| School | Area | PYP | MYP | DP | CP | Ages at the school | 2026/27 tuition |
|---|---|---|---|---|---|---|---|
| St. Dominic’s International School | São Domingos de Rana | Yes | Yes | Yes | No | 3 to 18 | €11,778 – €23,166 (fee page) |
| Oeiras International School | Barcarena, Oeiras | Yes | Yes | Yes | No | From Year 1 (age 5) to Year 13 | €13,980 – €22,406 (fee page) |
| International Sharing School Lisbon | Porto Salvo, Oeiras | Yes | Yes | Yes | No | Nursery to Grade 12 | €11,790 – €26,760 (fee page) |
| St. Julian’s School | Carcavelos | No | No | Yes | Yes | 3 to 18 | See the school’s fee page |
| Carlucci American International School of Lisbon (CAISL) | Linhó, Sintra | No | No | Yes | No | 3 to 18 | €12,128 – €23,532 (fee page) |
| TASIS Portugal | Sintra | No | No | Yes | No | Pre-K to Grade 12 | €13,007 – €24,308 (fee page) |
| PaRK International School | Alfragide (to Grade 12) | No | No | Yes | No | 1 to 18 | €9,830 – €22,200 (fee page) |
| King’s College School, Cascais | Cascais | No | No | Yes | No | 1 to 18 | €12,500 – €27,500 (fee PDF) |
Tuition ranges cover the youngest to the oldest year group. Entry fees, meals and transport come on top. Our fees guide compares the full cost.
Which schools teach the IB all the way through?
Three schools offer the full IB journey, from the Primary Years Programme to the Diploma. The IB calls this the “IB continuum”. It’s a good fit if you move often, or if your child already comes from an IB school.
St. Dominic’s has been an IB school since 1994, when the IB authorised its Diploma Programme. It runs the Primary Years Programme from Nursery to Grade 5, then the Middle Years Programme, then the Diploma in Grades 11 and 12. It also offers IB Diploma Courses, where a student takes separate IB subjects instead of the full Diploma.
Oeiras International School (OIS) offers the Primary Years Programme from Year 2 to Year 6 (ages 6 to 10), the Middle Years Programme from Year 7 to Year 11, and the Diploma in Years 12 and 13. The school says all its students sit the full Diploma.
International Sharing School Lisbon, in the Taguspark area of Porto Salvo, teaches the IB in English from Nursery to Grade 12.
Which schools switch to the IB Diploma at 16?
Most IB schools in the area teach their own curriculum first and start the IB Diploma in the last two years.
- St. Julian’s follows the English National Curriculum to GCSE, then offers the IB Diploma or the IB Career-related Programme in Years 12 and 13. Its Diploma has been authorised since 1986.
- CAISL is an American school. Every graduate earns an American High School Diploma, and the school says most students also take the IB Diploma in Grades 11 and 12.
- TASIS Portugal teaches Core Knowledge and Cambridge IGCSEs, then the IB Diploma in Grades 11 and 12. The school says every student in its Class of 2026 took the full Diploma. For how the two American schools compare, see CAISL vs TASIS Portugal.
- PaRK International School teaches bilingually up to 4.º ano, then follows Cambridge to IGCSE. Students then choose between A Levels and the IB Diploma.
- King’s College School, Cascais follows Cambridge to IGCSE. For Years 12 and 13, the school says its main offer is the IB Diploma, with A Levels for a small group of students.
A note on King’s College School, Cascais
IB Diploma authorised (IB school finder, since 15 May 2026). The school’s own website still describes it as a candidate school (checked 21 October 2026). The IB’s finder is the authoritative record of which schools are authorised, so we list King’s as an IB Diploma school.
Schools working towards the IB Diploma
Two more schools say they are IB Diploma Programme candidate schools. Candidate status gives no guarantee that the IB will grant authorisation.
| School | Area | Where they are | Source |
|---|---|---|---|
| Redbridge International School | Lisbon (Tapada da Ajuda campus) | The school says its application has reached the final stage of authorisation, after the IB’s verification visit. | School’s IB page |
| The Lisboan | Lisbon | The school plans to welcome its first Diploma students in September 2027, subject to authorisation. | School’s IB page |
The IB Career-related Programme
The Career-related Programme (CP) is for students aged 16 to 19 who want to combine some academic IB subjects with career-related study. In Portugal, the IB lists only St. Julian’s for it. The IB authorised it there on 30 April 2025. Students take it in Years 12 and 13, as an alternative to the full Diploma.
IB Diploma results: what each school publishes
Not every school publishes its results, and those that do report them in different ways. The figures below come from each school’s own website. The world average for the May 2026 exams was 30.88 points out of 45, according to the IB.
| School | Latest IB Diploma results the school publishes | Source |
|---|---|---|
| St. Julian’s | 2026: average 35.6 points, 100% pass rate, 87 students | Exam results |
| PaRK International School | 2026: average 35.5 points, top score 45 | Homepage |
| TASIS Portugal | 2026: average 34.8 points, 98% pass rate. Its 2026–27 school profile gives 34.6 | IB page, school profile (PDF) |
| CAISL | 2026: average 34 points, 100% pass rate | Academic success |
| Oeiras International School | 2026: 52 students, none below 24 points, 21 scored 36 or more. OIS no longer publishes an average. | IB results |
| St. Dominic’s | 2026: average 31 points, 83% pass rate, 78 students | Homepage |
| International Sharing School Lisbon | 2025: average 32 points (2026 not yet on its website) | University prep |
| King’s College School, Cascais | No results published yet. The IB authorised its Diploma in May 2026. | – |
Read averages with care. A school where every student takes the full Diploma can have a lower average than a school where only some do. OIS and TASIS say all their students sit the full Diploma. CAISL says most of its students do. St. Dominic’s also offers separate IB courses. When you visit, ask how many students in Year 13 take the full Diploma, and what happens to those who don’t.
Other IB Diploma schools around Lisbon
The IB lists 17 IB schools in Portugal. Besides the schools above, four more teach the Diploma in or near Lisbon. They are Portuguese colégios rather than international schools, and we haven’t profiled them yet.
- Colégio Planalto, Lisbon. The IB lists it as a boys’ school, authorised for the Diploma since 1994.
- Colégio Mira Rio, Lisbon (Telheiras). A girls’ school from 1.º ano that follows the Portuguese curriculum, then offers the IB Diploma. Authorised since 2018.
- Colégio Atlântico, Seixal, south of the river.
- St. Peter’s International School, Palmela, south of the river.
How to choose an IB school
Decide how much IB you want. If you move every few years, a full-continuum school (St. Dominic’s, OIS or ISS) keeps things the same from age 3 to 18. If you want a British or American school with the IB at the end, look at St. Julian’s, CAISL, TASIS, PaRK or King’s.
Ask about the full Diploma. Find out whether every student takes it, which subjects run at Higher Level, and whether the Career-related Programme or A Levels are an option.
Compare the full cost. Check the fee for the Diploma years, not just the year your child starts. Our fees guide lists entry fees and extras.
Check the year group. Each school places children by its own birthday rules. Our school year and age-to-grade guide shows how Portuguese, UK, US and IB years line up.
Visit. Our open days and enrolment calendar lists the dates schools have published. You’ll learn more in one morning at a school than from any table.
Last checked: 21 October 2026. Please confirm details with each school before you apply.
Sources
All checked on 21 October 2026.
- IB school finder, Portugal: the 17 IB schools in Portugal and the programmes each is authorised for.
- IB school pages: St. Dominic’s, Oeiras International School, St. Julian’s, CAISL, PaRK, King’s College School Cascais, Colégio Planalto, Colégio Mira Rio.
- IB: May 2026 DP and CP results: world average of 30.88 points.
- School pages: St. Dominic’s PYP and Diploma; OIS accreditations; St. Julian’s IB Diploma and CP; TASIS IB Diploma; King’s IB Diploma and curriculum; Redbridge IB Diploma; The Lisboan IB Diploma; Colégio Mira Rio; Colégio Atlântico IB; St. Peter’s International School.
- Results: the school pages linked in the results table.
- Ages, areas and fees come from our school profiles, which link each school’s official pages and fee documents.