Joseph Gurney Cannon, American lawyer and politician, 40th Speaker of the United States House of Representatives (died 1926)

Joseph Gurney Cannon was an American politician from Illinois and a leader of the Republican Party. Cannon represented parts of Illinois in the United States House of Representatives for twenty-three non-consecutive terms between 1873 and 1923; upon his retirement, he was the longest serving member of the United States Congress ever. From 1903 to 1911, he presided as Speaker of the House, becoming one of the most powerful speakers in United States history.

The speaker of the United States House of Representatives, commonly known as the speaker of the House or House speaker, is the presiding officer of the United States House of Representatives, the lower chamber of the United States Congress. The office was established in 1789 by Article I, Section II, of the U.S. Constitution. By custom and House rules, the speaker is the political and parliamentary leader of the House and is simultaneously its presiding officer, de facto leader of the body's majority party, and the institution's administrative head. Speakers also perform various other administrative and procedural functions. Given these many roles and responsibilities, the speaker usually does not personally preside over debates—that duty is instead delegated to members of the House from the majority party—nor regularly participate in floor debates.