Australian House of Representatives

The House of Representatives is the lower house of the bicameral Parliament of Australia, the upper house being the Senate. Its composition and powers are set out in Chapter I of the Constitution of Australia.

The term of members of the House of Representatives is a maximum of three years from the date of the first sitting of the House, but on only one occasion since Federation has the maximum term been reached. The House is almost always dissolved earlier, usually alone but sometimes in a double dissolution alongside the whole Senate. Elections for members of the House of Representatives have always been held in conjunction with those for the Senate since the 1970s.

A member of the House may be referred to as a "Member of Parliament" ("MP" or "Member"), while a member of the Senate is usually referred to as a "senator". Under the conventions of the Westminster system, the government of the day and the prime minister must achieve and maintain the confidence of this House in order to gain and remain in power.

The House of Representatives currently consists of 150 members, elected by and representing single member districts known as electoral divisions (commonly referred to as "electorates" or "seats"). The number of members is not fixed but can vary with boundary changes resulting from electoral redistributions, which are required on a regular basis. Prior to the 1984 election, the number of members increased from 125 to 148. It was reduced to 147 for the 1993 election, returned to 148 for the 1996 election, increased to 150 for the 2001 election, and stood at 151 for the 2022 Australian federal election. The 2025 election saw 150 seats contested.

The House of Representatives chamber is designed to seat up to 172 members, with provision for an ultimate total of 240 to be accommodated.

Each division elects one member using full-preferential voting. This voting system was put in place after the 1918 Swan by-election, which Labor unexpectedly won when two conservative parties of that era split a substantially larger conservative (and anti-Labor) vote between themselves. The Nationalist government of the time changed the lower house voting system from first-past-the-post to full-preferential voting, effective from the 1919 general election.