The 13th United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives. It met in Washington, D.C. from March 4, 1813, to March 4, 1815, during the fifth and sixth years of James Madison's presidency. The apportionment of seats in the House of Representatives was based on the 1810 United States census. Both chambers had a Democratic-Republican majority. The first two sessions were held at the Capitol building while the third, convened after the Burning of Washington, took place in the First Patent Building.

The count below identifies party affiliations at the beginning of the first session of this congress. Changes resulting from subsequent replacements are shown below in the "Changes in membership" section.

Following the 1810 census, the size of the House was increased to 182 seats from 142.

This list is arranged by chamber, then by state. Senators are listed by class, and representatives are listed by district.

Senators were elected by the state legislatures every two years, with one-third beginning new six-year terms with each Congress. Preceding the names in the list below are Senate class numbers, which indicate the cycle of their election. In this Congress, Class 1 meant their term ended with this Congress, requiring reelection in 1814; Class 2 meant their term began in the last Congress, requiring reelection in 1816; and Class 3 meant their term began in this Congress, requiring reelection in 1818.

The count below reflects changes from the beginning of the first session of this Congress.

Lists of committees and their party leaders.