Saint Thomas Choir School is an all-boys boarding school located in Manhattan, New York, dedicated to the education and training of approximately 30 choirboys from ages 8 to 14. It is one of three all-boarding, all-boys choral schools in the world (the other two being Westminster Abbey Choir School in England and Escolania de Montserrat in Spain).

The school is supervised by and receives financial support from the nearby Saint Thomas Church (Episcopal), whose choral ensemble performs music in the Anglican tradition at worship services, while offering a full concert series during the course of the school year. Starting in 2025, the school's educational programs will be operated by the Professional Children's School, a day school for child actors and performers, although the church will continue to offer music and religious instruction.

In the 2024-25 school year, the school had 26 students and 24 faculty and staff. It resides in a fifteen-story building located at 202 West 58th Street in midtown Manhattan, one block south of Central Park. Since 2005, the school has offered a summer residential Girl Chorister Course.

During the 2023-24 school year, 74% of students were on financial aid, which covered, on average, 74% of tuition.