The House of Representatives (; ; ) is the lower house of the National Assembly of Thailand, the legislative branch of the Thai government. The system of government of Thailand is that of a constitutional monarchy and a parliamentary democracy. The system of the Thai legislative branch is modelled after the Westminster system. The House of Representatives has 500 members, all of which are democratically elected: 375 members were directly elected through single constituency elections, while the other 125 are elected through party-list proportional representation. The roles and powers of the House of Representatives were enshrined in the Constitution of 2017.