The Act Prohibiting Importation of Slaves of 1807 (2 Stat. 426, enacted March 2, 1807) is a United States federal law that provided that no new slaves were permitted to be imported into the United States. It took effect on January 1, 1808, the earliest date permitted by the United States Constitution.

This legislation was promoted by President Thomas Jefferson, who called for its enactment in his 1806 State of the Union Address. He and others had promoted the idea since the 1770s. It reflected the force of the general trend toward abolishing the international slave trade which Virginia, followed by all the other states, had prohibited or restricted since then. South Carolina, however, had reopened its trade. Congress first regulated against the trade in the Slave Trade Act of 1794. The 1794 Act ended the legality of American ships participating in the trade. The 1807 law did not change that—it made all importation from abroad, even on foreign ships, a federal crime.

The domestic slave trade within the U.S. was not affected by the 1807 law. Indeed, with the legal supply of imported slaves terminated, the domestic trade increased in importance. In addition, some smuggling of slaves persisted.