The resident commissioner of Puerto Rico is a non-voting member of the United States House of Representatives elected by the voters of the U.S. Commonwealth of Puerto Rico every four years, the only member of the House of Representatives who serves a four-year term. Because the commissioner represents the entire territory of Puerto Rico irrespective of its population, and is not subject to congressional apportionment like those House members representing the 50 states, Puerto Rico's at-large congressional district is the largest congressional district by population in all of the United States.

The United States House of Representatives is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together, they comprise the national bicameral legislature of the United States. The House is charged with the passage of federal legislation, known as bills; those that are also passed by the Senate are sent to the president for signature or veto. The House's exclusive powers include initiating all revenue bills, impeaching federal officers, and electing the president if no candidate receives a majority of votes in the Electoral College.