A Vietnam veteran is an individual who performed active ground, naval, or air service in the Republic of Vietnam, or served the country as a nurse during the Vietnam War.

The term has been used to describe veterans who served in the armed forces of South Vietnam, the United States Armed Forces, and other South Vietnam–backed allies, whether or not they were stationed in Vietnam during their service. However, the more common usage distinguishes between those who served "in-country" and those who did not serve in Vietnam by referring to the "in-country" veterans as "Vietnam veterans" and the others as "Vietnam-era veterans." Regardless, the U.S. government officially refers to all as "Vietnam-era veterans."

In the United States, the term "Vietnam veteran" is not typically used in relation to members of the People's Army of Vietnam or the Viet Cong (also known as the National Liberation Front) due to the United States' alliance with South Vietnamese forces.

However, in many parts of east and southeast Asia, the term "Vietnam veteran" may also apply to allies of the North Vietnamese, including the People's Army of Vietnam, the Viet Cong (National Liberation Front), the People's Liberation Army of China, and the Korean People's Army of North Korea.

South Vietnamese veterans While the exact numbers are not entirely known, it is estimated that several million served in the South Vietnamese armed forces, the vast majority in the Army of the Republic of Vietnam (ARVN). From 1969 to 1971, there were around 22,000 ARVN combat deaths per year. The army reached its peak strength of about 1,000,000 soldiers in 1972. The official number of South Vietnamese personnel killed in action was 220,357.

Following the North Vietnamese victory on April 30, 1975, South Vietnamese veterans were arrested and detained in labor camps in desolate areas. The veterans and their families were detained without trial for decades at a time. After being released, they faced significant discrimination from the Communist government. A significant proportion of the surviving South Vietnamese veterans left the country for Western countries including the United States and Australia, either by or through the Humanitarian Operation (HO).

U.S. veterans According to the U.S. Department of Labor, the Vietnam Era Veterans' Readjustment Assistance Act of 1974 (VEVRAA) states, "A Vietnam era veteran" is a person who:

served on active duty anywhere in the world for a period of 180+ days, any part of which occurred between August 5, 1964, and May 7, 1975, and was discharged or released with anything other than a dishonorable discharge; was discharged or released from active duty for a service-connected disability if any part of such active duty was performed between August 5, 1964, and May 7, 1975."

In 2004, the U.S. Census Bureau reported there were 8.2 million Vietnam-era veterans who were living in the United States, with 2.59 million of them being reported to have actually served "in-country." More than 58,000 U.S. military personnel died as a result of the conflict. That includes deaths from all categories including deaths while missing, captured, non-hostile deaths, homicides, and suicides. The Department of Veterans Affairs recognizes veterans that served in the country, then known as the Republic of Vietnam, from February 28, 1961, to May 7, 1975, as being eligible for such programs as the department's Readjustment Counseling Services program, also known as the Vet Centers. The Vietnam War was the last American war in which the U.S. government employed conscription.

American servicemen who served between January 9, 1962, and May 7, 1975, are presumed to have been exposed to herbicides, such as Agent Orange.U.S. Department of Veterans Affairs, Office of Research and Development, "Vietnam Veterans"

PTSD Many Vietnam veterans suffered from post-traumatic stress disorder (PTSD) in unprecedented numbers, with PTSD affecting as many as 15.2% of Vietnam veterans. The condition became a focus of clinical study in the 1980s, including The Trauma of War: Stress and Recovery in Viet Nam Veterans (1985), which described post-traumatic stress disorder in Vietnam veterans through clinical cases and discussed approaches to treatment. Referred to as the first "pharmacological war" in history, the U.S. war in Vietnam was so called because of the unprecedented level of psychoactive drugs that U.S. servicemen used. The U.S. military had routinely provided heavy psychoactive drugs, including amphetamines, to American servicemen, which left them unable to process adequately their war traumas at the time. The U.S. armed forces readily distributed large amounts of "speed" (stimulants), in the form of Dexedrine (dextroamphetamine), an amphetamine twice as strong as Benzedrine, to American servicemen. Soldiers embarking on long-range reconnaissance missions or ambushes, according to standard military instruction, were supposed to be given 20 milligrams of dextroamphetamine for 48 hours of combat readiness. But this instruction for heavy drugs was rarely followed: the drug was issued, according to veterans, "like candies," with little or no attention paid to the dose and frequency of administering the drug. In the period 1966–1969, the U.S. military provided 225 million tablets of stimulants, mostly dextroamphetamine, according to a 1971 report by the Select Committee on Crime of the U.S. House of Representatives.The Atlantic, 8 Apr. 2016, "The Drugs That Built a Super Soldier: During the Vietnam War, the U.S. Military Plied Its Servicemen with Speed, Steroids, and Painkillers to Help Them Handle Extended Combat" According to a member of a long-range reconnaissance platoon, the drugs "gave you a sense of bravado as well as keeping you awake. Every sight and sound was heightened. You were wired into it all and at times you felt really invulnerable." Servicemen who participated in infiltrating Laos, a secret intervention by the United States in the Laotian Civil War, on four-day missions received 12 tablets of an opioid (Darvon), 24 tablets of codeine (an opioid analgesic), and 6 pills of dextroamphetamine. Also, those serving in special units departing for a tough, long mission were injected with steroids.

However, pumping the soldiers with speed and heavy anti-psychotics like Thorazine (chlorpromazine) came with a price that veterans paid later. By alleviating the symptoms, the anti-psychotics and narcotics offered temporary relief. However, these serious drugs administered in the absence of professional psychiatric supervision and proper psychotherapy merely suppressed the problems and symptoms, but veterans years later often experienced those problems untreated and amplified. This is a large part of the reason why very few servicemen, compared to previous wars, required medical evacuation due to combat-stress breakdowns, but PTSD levels among veterans after the war are at unprecedented levels compared to previous wars.

US nurses Between 1955 and 1975, around 7,000 American women travelled to South-East Asia to serve their country as nurses. These women were often young, and either followed their fathers, brothers or husbands to war, or went of their own accord, driven by their own beliefs or passion for medicine. 90% of these women were there voluntarily and were fresh out of nursing school, aged around 23. A few of the Army nurses were also men.Once there, they were quickly exposed to harsh conditions (for which they had rarely been trained), such as 12–14 hour shifts, challenging weather conditions and mortar attacks. These circumstances likely triggered trauma in all of them and, as was later discovered, PTSD.

In the early 1970s, women who were able to return home were not recognised as veterans, as they had not been directly on the front line. This made it difficult, or even impossible, for them to readjust to normal everyday life. In the years that followed, however, Army nurses gained increasing recognition and were accorded the respect they deserved.

Nine nurses died in Vietnam, two of whom were male: Captain Eleanor Alexander, Second Lieutenant Carol Drazba, First Lieutenant Pamela Donovan, Lieutenant Colonel Annie Graham, Second Lieutenant Elizabeth Jones, First Lieutenant Sharon Lane, First Lieutenant Jerome Olmsted, Second Lieutenant Hedwig Orlowski, First Lieutenant Kenneth Shoemaker, and Captain Mary Klinker, USAF.

Veterans from other nations

Nationals of other nations fought in the American-led anti-communist coalition, usually as armed forces of allied nations, such as Australia, New Zealand, Thailand, and South Korea, but sometimes as members of the U.S. Armed Forces. The Republic of China (Taiwan), Spain, and the Philippines contributed assistance in non-combat roles.

Australian veterans Australia deployed approximately three battalions of infantry, one regiment of Centurion tanks, three RAAF Squadrons (2SQN Canberra Bombers, 9SQN Iroquois Helicopters, and 35 SQN Caribou Transports), 2 batteries of Royal Australian Artillery and a Special Air Service Regiment (SASR) Squadron. The Royal Australian Navy (RAN) performed a variety of operational tasks at sea, ashore and in the air. The 1st Australian Task Force consisted of Army, Navy, and Air Force personnel and commanded all Australian operations from 1966 until 1972. 1st Australian Logistic Support Group (1 ALSG) was 1 ATF's ground support unit, composed of engineer, transport, ordnance, medical, and service corps units. Australian Army training teams followed the withdrawal of combat forces in 1971. According to the Australian Government Nominal Roll of Vietnam Veterans 13,600 members of the Royal Australian Navy, 41,720 members of the Australian Army, and 4,900 members of the Royal Australian Air Force served in Vietnam from 1962 to 1975. According to official statistics, 501 personnel died or went missing in action during the Vietnam War and 2,400 were wounded.

Canadian veterans During the Vietnam era, more than 30,000 Canadians served in the U.S. Armed Forces; 110 Canadians died in Vietnam, and seven are listed as missing in action. Fred Griffin, a military historian with the Canadian War Museum, estimated in Vietnam Magazine (Perspectives) that approximately 12,000 of these personnel served in Vietnam. Most of these were Canadians who lived in the United States. The military of Canada did not participate in the war effort.

New Zealand veterans