Oeiras International School (OIS) is located in Portugal and offers a comprehensive International Baccalaureate (IB) Continuum, including the Primary Years Programme (PYP), Middle Years Programme (MYP), and Diploma Programme (DP). The school is distinguished by its strong commitment to sustainability, as evidenced by its participation in the international Eco-Schools programme and its Green Flag Award for 2024–2025. OIS is set within a historical palace and surrounded by natural landscapes, providing students with opportunities for outdoor learning and environmental projects. The school also emphasizes intercultural learning with a diverse student body from over 40 countries, fostering a multilingual and inclusive community.