Assumption College Thonburi (Thai: โรงเรียนอัสสัมชัญธนบุรี) is a private Catholic school located in Bangkok, Thailand. It is the eighth private school founded by the St. Gabriel Foundation in Thailand. The school was founded by Bro. John Mary Jesus Salas Esquiroz of the Saint Gabriel foundation in 1961. The school provides education to students from grade 1 through 12 (K-12).