Stamford American International School (SAIS) is a co-educational international school in Singapore. The school is owned and operated by Cognita and enrolled its first students in August 2009.

Stamford American has two campuses. The Early Learning Village, which caters to students from Pre-Nursery to KG2, is located at Chuan Lane, 2.6 km (1.6 mi) away from the Elementary and Secondary Campus on Woodleigh Lane, near Woodleigh MRT station, which are dedicated to students from Grades 1 to 12.

In August 2008, the Government of Singapore listed the site of the former Upper Serangoon Secondary School as available for the construction of a new international school, in part to address the need for businesses seeking to recruit employees from other countries. Potential hires were reluctant to take work where so few places existed in international schools to serve their children. In November, the government announced that Cognita had been chosen to build a new school on the site.

The school first opened in August 2009 at the Foundation Campus, located at 11 Lorong Chuan, while the purpose-designed permanent campus was being built. Stamford American International School's new $300 million campus was completed and opened in August 2012.

In August 2017, Stamford American opened the 'world's largest pre-school' in collaboration with the Australian International School (AIS). At 50,000 square meters with five buildings and more than 100 classrooms, the Early Learning Village caters to children aged 2 months to six years.

Stamford American's student body comprises over 75 nationalities across 6 continents. The majority of Stamford American's students come from the United States, Canada, UK, Japan, Australia, New Zealand, and China. Cultural events such as the week-long International Fiesta organized by Stamford's Parent Teacher Association (PTA), Lunar New Year, Deepavali, and Christmas are celebrated in school.

The students graduate with a US-accredited Stamford High School Diploma with the opportunity to pursue International Baccalaureate Diploma or an Advanced Placement Diploma. The school offers over 40 IB courses and more than 20 AP courses.

Stamford American offers the opportunity to pursue the International Baccalaureate (IB) Diploma, Advanced Placement (AP) Diploma, or the Business and Technical Education Council (BTEC) Diploma. Stamford American International School is accredited by the Accrediting Commission for Schools, Western Association of Schools and Colleges (WASC). It is also an authorized school for the IB Primary Years Programme (PYP), the IB Middle Years Programme (MYP), and the IB Diploma Programme (IBDP). Stamford American is an IB World School.

The typical student-teacher ratio is 5–11:1 (Nursery to KG2), 12–24:1 (G1–G5) and 24:1 (G6–G11).

Stamford offers optional after school mother-tongue programs for all students. The 12 languages are Danish, Dutch, Filipino, Finnish, French, Hebrew, Hindi, Norwegian, Portuguese, Russian, Spanish, and Swedish. Students in the program have access to native teachers, classroom facilities, a library, and event spaces. The Stamford World Language Program offers three languages: Mandarin, Spanish, and English. The program offers Bilingual Mandarin and English from 3 to 10 years, Daily Mandarin or Spanish for 18 months to 11 years, and English as an Additional Language Program for 5 to 16 years.

The Academic Field Studies Program starts in Grade 3 at Stamford American within environments beyond the classroom. It was developed in consultation with the JUMP! Foundation.

The class of 2021 graduates completed the IB course with a 100% pass rate. The average AP score for 2021 was 3.3, with over 70% of the exam scores being 3 or above. In 90% of the AP subjects, over half the candidates scored a 3 or above. Two students earned a Distinction and a Merit, respectively, for the BTEC Subsidiary Diploma in Performing Arts: Acting. The class of 2021 has been accepted into universities in 18 countries, with notable acceptances from Boston University, New York University, National University of Singapore, amongst others. The university destinations include the US, UK, Canada, Singapore, the Philippines, and Finland, amongst others.

Stamford American's co-curricular activities (CCA) program has around 350 activity choices throughout the year for students from Pre-K to Grade 12, with over 75% of Stamford American students enrolled (3,389 CCA places). The school has an online CCA registration program, which includes an online CCA brochure. The program incorporates activities from financial market trading to Calligraphy; Model United Nations to Aerospace.

Stamford American provides productions every year at the Reagan Theater. Weekly drama classes begin in Kindergarten and continue to Grade 10. Stamford American also offers an International Baccalaureate Diploma in Theater and a BTEC in Performing Arts (Acting).

Students at the Early Learning Village (ELV) were offered music at the age of 18 months. From the age of 5, children can move on to cello lessons. Music is a part of the curriculum for students up to Grade 8, while students in Grade 9 and Grade 10 can choose music for their Middle Years Program (MYP) arts allocation. In Grade 11 and 12, students can opt for it as their arts subject within the Diploma Program (DP). More than 400 students are enrolled in the Instrumental Music Program.

Stamford American offers sports for Kindergarten to Grade 12. Stamford American is a member school of the South East Asia Student Activities Conference (SEASAC).

The Stamford American community, in partnership with World Assistance for Cambodia, built the Cambodia Hope School in the Boribo Province of Cambodia. In 2016, students and teachers from Stamford American visited the school. Students at Hope School received stationery and sports equipment, while English as a second language resources were distributed to local teachers.

In 2017, together with the Parent Teacher Association (PTA), Stamford American students founded the Christmas Giving Tree. They gifted the Singapore Cancer Society, SOSD, Make-A-Wish Foundation, Waterways, Willing Hearts, Ronald McDonald House, and the Autism Resource Center (ARC).

Stamford American has two centrally located campuses that are linked by a shuttle bus service.

• 3 swimming pools
• 2 air-conditioned indoor sports arenas
• 2 libraries
• Rooftop tennis courts
• Dance studios
• Rock-climbing walls
• Multipurpose sports field
• Indoor virtual golf studio
• 500-seat theater
• Innovation Center and Maker Space with 3D printers, robots, and other electronics

• 6 ultraviolet-protected outdoor areas
• Infant Care Pod with sensory play areas
• 20-meter pool with adjustable lanes and resting benches
• The Hive, an air-conditioned multipurpose gymnasium for sports and performances

• Official website