A war veteran (from Latin vetus, meaning "old") is a person who has or is working in the armed forces, or a person who has had long service or experience in an occupation or office.

For the most part, war veterans are treated with great respect and honor for their contribution to the world and country. Many countries have longstanding traditions, ceremonies, and holidays to honor veterans. In Russia, a tradition was established after the Second World War, where newly married couples would on their wedding day visit a military cemetery. In France, for instance, those wounded in war are given the first claim on any seat on public transit. Most countries have a holiday such as Veterans Day to honor veterans, along with the war dead. There are exceptions to this: veterans of unpopular conflicts, such as the Vietnam War, have been discriminated against. Others, such as veterans of conflicts like the Korean War, are often forgotten (even though the casualty rate in Korea was higher than that experienced in the Vietnam War) when compared with those who fought in the World Wars. In some countries with strong anti-military traditions (e.g., Germany after 1945) veterans are neither honored in any special way, nor have their dedicated Veterans Day.

United States

The most common usage is for former armed services personnel. A veteran is one who has served in the armed forces, especially one who has served in combat. It is especially applied to those who served for an entire career, usually of 20 years or more, but may be applied for someone who has only served one tour of duty. A common misconception is that one had to have either been in combat and/or has retired from active duty to be called a military veteran.

Veterans' benefits in the United States

President Abraham Lincoln, in his second inaugural address, in 1865 towards the end of the US Civil War, famously called for good treatment of veterans: "to care for him who shall have borne the battle, and for his widow, and his orphan". The American Civil War produced veterans' organizations, such as the Grand Army of the Republic. The treatment of veterans changed after the First World War. In the years following, discontented veterans became a source of instability. They could quickly organize, had links to the army, and often had arms themselves. Veterans played a central role in the post-World War I instability of Germany, while in the United States, the Bonus Army of unemployed veterans was one of the most important protest movements of the Great Depression, marching on Washington, DC, to get a claimed bonus that Congress had promised them.

Each state (of the United States) sets specific criteria for state-specific veterans' benefits. For federal medical benefits from the Department of Veterans Affairs (VA) hospitals, prior to 7 September 1980 the veteran must have served at least 180 days of active duty, after the above-mentioned date, the veteran must have served at least 24 months. However, if the veteran was medically discharged and receives a VA service-connected disability stipend, the time limits are not applicable.