The 28th 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, 1843, to March 4, 1845, during the third and fourth years of John Tyler's presidency. The apportionment of seats in this House of Representatives was based on the 1840 United States census. The Senate had a Whig majority, and the House had a Democratic majority.

During this congress, two Senate seats were added for the new state of Florida.

Following the 1840 United States census, Congress reapportioned the House to include 223 seats. During this congress, one House seat was added for the new state of Florida.

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 1844; Class 2 meant their term began in the last Congress, requiring reelection in 1846; and Class 3 meant their term began in this Congress, requiring reelection in 1848.

Representatives are listed by their district numbers.

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

Lists of committees and their party leaders.