The Foraker Act (Pub. L. 56–191, 31 Stat. 77, enacted April 12, 1900), officially called the Organic Act of 1900 and most commonly known by the name of its sponsor, Senator Joseph B. Foraker, (R-Ohio), is an organic act of the 56th United States Congress that was signed into law by President William McKinley on April 12, 1900, to take effect May 1, 1900. The Act replaced the military government of Puerto Rico, which was established by the United States after the annexation of the archipelago and island during the Spanish–American War in 1898, with a civil insular government under the continued federal jurisdiction of the United States as the local administration of an unincorporated territory. It served as the primary organic law for the government of Puerto Rico and its relation with the United States until it was superseded by the Jones–Shafroth Act of 1917.

The Foraker Act established a civil government in Puerto Rico modeled after the federal government of the United States. It divided the local government of the unincorporated territory into three branches: an executive, consisting of a Governor and an 11-member Executive Council appointed by the President of the United States, a legislative, composed of bicameral Legislative Assembly, with the Executive Council as its upper chamber and a 35-member House of Delegates elected by the residents of Puerto Rico as its lower chamber, and a judicial, headed by a chief justice and a district judge appointed by the President. The Act created the office of Resident Commissioner, a non-voting member to the United States House of Representatives elected by the residents of Puerto Rico. It also established Puerto Rican citizenship and extended American nationality to Puerto Ricans.

The Foraker Act extended some measure of local self-government to Puerto Rico with the creation of a popularly elected lower chamber of the legislative branch, but the preponderant control of the local government of Puerto Rico was retained by the United States through the authority of the President to appoint the entire executive branch and half of the legislative branch, and the power of the United States Congress to annul any law enacted by the legislative branch. However, the residents of Puerto Rico had some opportunity to influence executive policies through the five appointed members of the Executive Council, who were required to be native Puerto Ricans by the Act.

In 1900, while Senator Joseph B. Foraker presented the bill that would become the Foraker Act, the first organic law establishing civil government in Puerto Rico, he received a total of $44,000 in payments from Standard Oil Company. The relationship was documented in more than twenty letters between Foraker and Standard Oil vice president John D. Archbold, later published by William Randolph Hearst in 1912.

That same year, Foraker's annual Senate salary was $5,000. Historian Nieve de los Angeles Vazquez documents in El Jefe that the Standard Oil payments exceeded his Senate salary by nearly nine times in the year he designed Puerto Rico's civil governance framework.

A brief summery of sections of the Foraker Act of 1900 is as follows:

2 Required that the same tariffs, customs, and duties be levied collected and paid upon all articles imported into Puerto Rico from ports other than those of the United States which are required by law to be collected upon importation into the United States from foreign countries.

3 Implemented a temporary tariff on goods transferred between Puerto Rico and the United States. This tariff was set to expire either upon the implementation of local taxation by the Legislature of Puerto Rico sufficient to "meet the necessities of the government" or on the first day of March 1902.