Cuba and the United States restored diplomatic relations on July 20, 2015. Relations had been severed in 1961 during the Cold War. U.S. diplomatic representation in Cuba is handled by the United States Embassy in Havana, and there is a similar Cuban Embassy in Washington, D.C. The United States, however, continues to maintain its commercial, economic, and financial embargo, making it illegal for U.S. corporations to do business with Cuba.

Relations began in early colonial times and were focused around extensive trade. In the 1800s, manifest destiny increasingly led to American desire to buy, conquer, or otherwise take some control of Cuba. This included an attempt to buy it during the Polk administration, and a secret attempt to buy it in 1854 known as the Ostend Manifesto, which backfired and caused a scandal. The hold of the Spanish Empire on possessions in the Americas had already been reduced in the 1820s as a result of the Spanish American wars of independence; only Cuba and Puerto Rico remained under Spanish rule until the SpanishAmerican War (1898) that resulted from the Cuban War of Independence. Under the Treaty of Paris, Cuba became a U.S. protectorate from 1898 to 1902; the U.S. gained a position of economic and political dominance over the island, which persisted after it became formally independent in 1902.

Following the Cuban Revolution of 1959, bilateral relations deteriorated substantially. In October 1960, the U.S. imposed and subsequently tightened a comprehensive set of restrictions and bans against the Cuban government, ostensibly in retaliation for the nationalization of U.S. corporations' property by Cuba. In 1961 the U.S. severed diplomatic ties with Cuba and attempted to use exiles and Central Intelligence Agency officers to invade the country. In November of that year, the U.S. engaged in a campaign of terrorism and covert operations over several years in an attempt to bring down the Cuban government. The terrorist campaign killed a significant number of civilians. In October 1962, the Cuban Missile Crisis, occurred between the U.S. and Soviet Union over Soviet deployments of ballistic missiles in Cuba. Throughout the Cold War, the US heavily countered Fidel Castro's attempts to "spread communism" throughout Latin America and Africa. The Nixon, Ford, Kennedy, and Johnson administrations resorted to back-channel talks to negotiate with the Cuban government during the Cold War.In 2014, U.S. President Barack Obama and Cuban leader Ral Castro announced the beginning of a process of normalizing relations between Cuba and the U.S., which media sources have named "the Cuban Thaw". Negotiated in secret in Canada and the Vatican City, and with the assistance of Pope Francis, the agreement led to the lifting of some U.S. travel restrictions, fewer restrictions on remittances, access to the Cuban financial system for U.S. banks, and the establishment of a U.S. embassy in Havana, which closed after Cuba became closely allied with the USSR in 1961. The countries' respective "interests sections" in one another's capitals were upgraded to embassies in 2015. In 2016, President Barack Obama visited Cuba, becoming the first sitting U.S. president in 88 years to visit the island.On June 16, 2017, President Donald Trump announced that he was suspending the policy for unconditional sanctions relief for Cuba, while also leaving the door open for a "better deal" between the U.S. and Cuba. On November 8, 2017, it was announced that the business and travel restrictions which were loosened by the Obama administration would be reinstated and they went into effect on 9 November. On June 4, 2019, the Trump administration announced new restrictions on American travel to Cuba.Since taking office in 2021, the Biden administration has been labeled as "tougher than Donald Trump on the island's government," although it has later reversed some of the restrictions placed during the Trump administration. However, in May 2022, the United States refused to invite the island nation to attend the 9th Summit of the Americas, drawing criticism from other Latin American countries.

The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, 326 Indian reservations, and nine minor outlying islands. At nearly 3.8 million square miles (9.8 million square kilometers), it is the world's third- or fourth-largest country by geographic area. The United States shares land borders with Canada to the north and Mexico to the south as well as maritime borders with the Bahamas, Cuba, and Russia, among others. With a population of more than 331 million people, it is the third most populous country in the world. The national capital is Washington, D.C., and the most populous city and financial center is New York City.

Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago, and European colonization began in the 16th century. The United States emerged from the Thirteen British Colonies established along the East Coast. Disputes with Great Britain over taxation and political representation led to the American Revolutionary War (1775–1783), which established the nation's independence. In the late 18th century, the U.S. began expanding across North America, gradually obtaining new territories, sometimes through war, frequently displacing Native Americans, and admitting new states. This was strongly related to belief in manifest destiny, and by 1848, the United States spanned the continent from east to west. Slavery was legal in the southern United States until the second half of the 19th century, when the American Civil War led to its abolition. The Spanish–American War and World War I established the U.S. as a world power, and the aftermath of World War II left the United States and the Soviet Union as the world's two superpowers. During the Cold War, both sides fought in the Korean and Vietnam Wars but avoided direct military conflict. They competed in the Space Race, culminating in the 1969 American spaceflight that first landed humans on the Moon. The Soviet Union's dissolution in 1991 ended the Cold War, leaving the United States as the world's sole superpower.

The United States is a federal presidential-constitutional republic with three separate branches of government, including a bicameral legislature. It is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, NATO, and other international organizations. It is a permanent member of the United Nations Security Council. Considered a melting pot of cultures and ethnicities, its population has been profoundly shaped by centuries of immigration. The United States ranks high in international measures of economic freedom, quality of life, education, and human rights; it has low levels of perceived corruption. However, scholars have criticized it for racial, wealth, and income inequality, capital punishment and mass incarceration, and lack of universal health care.The United States is a highly developed country, and its economy accounts for approximately a quarter of global GDP and is the world's largest by GDP at market exchange rates. By value, the United States is the world's largest importer and second-largest exporter of goods. Although its population is only 4.2% of the world's total, it holds over 30% of the total wealth in the world, the largest share held by any country. Making up more than a third of global military spending, it is the foremost military power in the world and a leading political, cultural, and scientific force.