Sukhothai Thammathirat Open University was officially established by Royal Charter on September 5, 1978 as Thailand's eleventh state university to provide the people with increased education opportunities. His Majesty King Bhumibol Adulyadej, King Rama IX, bestowed the name "Sukhothai Thammathirat Open University" in honor of King Rama VII, one of whose titles before his accession to the throne was "Prince Sukhothai Thammaracha". It was the first open university in Southeast Asia to use a distance teaching/learning system.
STOU received its first academic class on 1 December 1980, beginning with three schools of study: Educational Studies, Liberal Arts and Management Science. From 1979 to 1984, STOU shared space with other state agencies and universities. In 1981, the university acquired its current property in Pakkret district of Nonthaburi Province, and began operating from the new location on 9 December 1984. Today the university has 12 schools of study with undergraduate, graduate and certificate programs.