General elections were held in Siam on 29 January 1948. Following the 1947 coup, the unicameral parliament elected in 1946 was abrogated. It was replaced by a bicameral parliament with a 100-seat appointed Senate and a 99-member House of Representatives.
Voter turnout was 30%.
In order to comply with the constitutional requirement of one member of the House of Representatives for every 150,000 citizens, supplementary elections were held in June 1949.