United States President John F. Kennedy sends 18,000 military advisors to South Vietnam.

John Fitzgerald Kennedy, also known as JFK, was the 35th president of the United States, serving from 1961 until his assassination in 1963. He was the first Roman Catholic and youngest person elected president at 43 years. Kennedy served at the height of the Cold War, and the majority of his foreign policy concerned relations with the Soviet Union and Cuba. A member of the Democratic Party, Kennedy represented Massachusetts in both houses of the United States Congress prior to his presidency.

South Vietnam, officially the Republic of Vietnam, was a country in Southeast Asia that existed from 1955 to 1975. It first garnered international recognition in 1949 as the associated State of Vietnam within the French Union, with its capital at Saigon. Since 1950, it was a member of the Western Bloc during the Cold War. Following the 1954 partition of Vietnam, it became known as South Vietnam and was established as a republic in 1955. South Vietnam was bordered by North Vietnam to the north, Laos to the northwest, Cambodia to the southwest, and Thailand across the Gulf of Thailand to the southwest. Its sovereignty was recognized by the United States and 87 other nations, though it failed to gain admission into the United Nations as a result of a Soviet veto in 1957. It was succeeded by the Republic of South Vietnam in 1975. In 1976, the Republic of South Vietnam and North Vietnam merged to form the Socialist Republic of Vietnam.

November 18 is the 322nd day of the year in the Gregorian calendar; 43 days remain until the end of the year.