The most renowned international high schools in Hangzhou, China, are the International School of Hangzhou (ISH) and Hangzhou No. 1 High School International Department. These institutions are highly regarded for their rigorous academic programs, diverse student body, and strong college preparation.

The International School of Hangzhou (ISH) is an independent, co-educational, and non-sectarian school that offers the International Baccalaureate (IB) Diploma Programme. ISH has been recognized for its exceptional educational standards and is known for its strong emphasis on global citizenship and cultural understanding. According to the 2020 IB World Schools Yearbook, ISH has a student body of approximately 1,200 students from over 50 countries, reflecting the school's commitment to fostering an international community.

Hangzhou No. 1 High School International Department is another top choice for international students. This department offers both the Chinese National Curriculum and the International Baccalaureate Diploma Programme. The school has a long-standing reputation for academic excellence and is well-known for its comprehensive approach to education, which includes a strong focus on both Chinese and international curricula. According to the China Education Ministry's 2019 report on international education, Hangzhou No. 1 High School has a student body of over 2,000, with a significant number of international students.

The reasons for these schools' prominence can be attributed to several factors. Firstly, both ISH and Hangzhou No. 1 High School International Department have a strong track record of preparing students for top universities around the world. The IB Diploma Programme, in particular, is recognized by universities worldwide for its rigorous academic standards and emphasis on critical thinking and global awareness. Secondly, both schools offer a diverse range of extracurricular activities and community service opportunities, which help students develop well-rounded personal and social skills. Lastly, the schools' locations in Hangzhou, a vibrant and historically significant city, provide students with a rich cultural environment that enhances their educational experience.