A crossbencher is a minor party or independent member of some legislatures, such as the Parliament of Australia. In the British House of Lords the term refers to members of the parliamentary group of non-political peers. They take their name from the crossbenches, between and perpendicular to the government and opposition benches, where crossbenchers sit in the chamber.

Crossbench members of the British House of Lords are not aligned to any particular party. Until 2009, these included the Law Lords appointed under the Appellate Jurisdiction Act 1876. In addition, former Speakers of the House of Commons (such as Lord Martin of Springburn and Baroness Boothroyd) and former Lord Speakers of the House of Lords (such as Baroness Hayman and Baroness D'Souza), who by convention are not aligned with any party, also sit as crossbenchers. There are also some non-affiliated members of the House of Lords who are not part of the crossbencher group; this includes some officers, such as the Lord Speaker, and others who are associated with a party but have had the whip withdrawn. Although non-affiliated members, and members of small parties, sometimes physically sit on the crossbenches, they are not members of the crossbench parliamentary group.

An "increasing number" of crossbenchers have been created peers for non-political reasons. Since its establishment in May 2000, the House of Lords Appointments Commission has nominated a total of 67 non-party-political life peers who joined the House of Lords as crossbenchers. As of 26 October 2025^[update], there are 178 crossbenchers, making up approximately 22 percent of the sitting members in the House of Lords. The Crossbench is typically the third-largest peerage group after the Conservative and Labour benches. From April 2007 to 2009, the number of crossbenchers was higher than the number of Conservative peers for the first time.

Although the Lords Spiritual (archbishops and senior bishops of the Church of England) also have no party affiliation, they are not considered crossbenchers and do not sit on the crossbenches, their seats being on the Government side of the Lords Chamber.

The crossbenchers do not take a collective position on issues, and so have no whips; however, they do elect from among themselves a convenor for administrative purposes, and to keep them up to date with the business of the House. The current convenor is Charles Hay, 16th Earl of Kinnoull, who took the office in April 2023. While convenors are not part of the "usual channels" (i.e. the party whips who decide the business of the House), they have been included in their discussions in recent years.

The following have served as Convenor of the Crossbenchers:

In the federal Parliament of Australia as well as the parliaments of the Australian states and territories, the term crossbencher refers to any minor party and independent members of parliament. More precisely, a crossbencher is any member who is not part of the governing party or parties, nor the party or parties forming what is known as the official opposition, sometimes known simply as the opposition. Unlike the United Kingdom, the term is used by both the lower and upper houses of each parliament (where applicable), who sit on the crossbenches between the government and opposition benches.

Federal elections in the early 21st century have seen an increase in the size and power of the crossbench in both houses of parliament. The Australian Parliament as elected at the 2010 election was the first hung parliament in the House of Representatives since the election of 1940, with the Australian Labor Party and the Coalition winning 72 seats each of 150 total. Six crossbenchers held the balance of power: Greens MP Adam Bandt and independent MP Andrew Wilkie, Rob Oakeshott and Tony Windsor declared their support for Labor on confidence and supply, independent MP Bob Katter and National Party of Western Australia MP Tony Crook declared their support for the Coalition on confidence and supply. The resulting 76–74 margin entitled Labor to form a minority government.