Ruamrudee International School (RIS) was founded in 1957 by a group of Redemptorist priests of Holy Redeemer Church with help from expatriate parishioners and a handful of local Thai students. The school began as the two classrooms for children of expatriates in the Holy Redeemer School and was given its current name when it moved into its own building in 1963. In 1966, it changed from the British to the American system. In August 1992, the school moved to a 14-acre campus in the suburban district of Minburi. The school has been ranked among the top five international schools in Thailand.