The Paris Peace Accords officially ends the Vietnam War. Colonel William Nolde is killed in action becoming the conflict's last recorded American combat casualty.

The Paris Peace Accords, officially the Agreement on Ending the War and Restoring Peace in Viet Nam, was a peace agreement signed on January 27, 1973, to establish peace in Vietnam and end the Vietnam War. It took effect at 8:00 the following day. The agreement was signed by the governments of the Democratic Republic of Vietnam ; the Republic of Vietnam ; the United States; and the Provisional Revolutionary Government of the Republic of South Vietnam (PRG), which represented South Vietnamese communists. US ground forces had begun to withdraw from Vietnam in 1969, and had suffered from deteriorating morale during the withdrawal. By the beginning of 1972 those that remained had very little involvement in combat. The last American infantry battalions withdrew in August 1972. Most air and naval forces, and most advisers, also were gone from South Vietnam by that time, though air and naval forces not based in South Vietnam were still playing a large role in the war. The Paris Agreement removed the remaining US forces. Direct US military intervention was ended, and fighting between the three remaining powers temporarily stopped for less than a day. The agreement was not ratified by the US Senate.

The Vietnam War was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam and South Vietnam and their allies. North Vietnam was supported by the Soviet Union and China, while South Vietnam was supported by the United States and other anti-communist nations. The conflict was the second of the Indochina wars and a proxy war of the Cold War between the Soviet Union and US. The Vietnam War was one of the postcolonial wars of national liberation, a theater in the Cold War, and a civil war, with civil warfare a defining feature from the outset. Direct US military involvement escalated from 1965 until its withdrawal in 1973. The fighting spilled into the Laotian and Cambodian Civil Wars, which ended with all three countries becoming communist in 1975.

January 27 is the 27th day of the year in the Gregorian calendar; 338 days remain until the end of the year.