The 34th 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, 1855, to March 4, 1857, during the last two years of Franklin Pierce's presidency. The apportionment of seats in the House of Representatives was based on the 1850 United States census. The Whig Party, one of the two major parties of the era, had largely collapsed, although many former Whigs ran as Republicans or as members of the "Opposition Party." The Senate had a Democratic majority, and the House was controlled by a coalition of Representatives led by Nathaniel P. Banks, a member of the American Party.

The presidency of Franklin Pierce began on March 4, 1853, when Franklin Pierce was inaugurated, and ended on March 4, 1857. Pierce, a Democrat from New Hampshire, took office as the 14th United States president after routing Whig Party nominee Winfield Scott in the 1852 presidential election. Seen by fellow Democrats as pleasant and accommodating to all the party's factions, Pierce, then a little-known politician, won the presidential nomination on the 49th ballot of the 1852 Democratic National Convention. His hopes for reelection ended after losing the Democratic nomination at the 1856 Democratic National Convention.