List of military legions

Ancient Rome

• List of Roman legions
• * Theban Legion, a Roman legion whose members, according to a long-lasting tradition, were massacred for their Christian beliefs

  18th century

• Western Legion and Eastern Legion, Greek rebel forces under Russian command in the Orlov Revolt
• Lee's Legion, an infantry and cavalry unit of the American Continental Army
• Armand's Legion, an American dragoon unit
• British Legion , made up of Loyalist American infantry and cavalry
• Lauzun's Legion, composite corps of the French Army comprising cavalry, infantry and artillery elements, mostly recruited from foreign mercenaries
• Pulaski's Legion, one of the few cavalry regiments in the American Continental Army, later merged into Armand's Legion
• Legion of the United States, an early United States land force commanded by Anthony Wayne
• French Revolutionary Legion of the Mississippi, a French commissioned force of Americans commanded by George Rogers Clark

  French Revolutionary and Napoleonic Wars

• Légion des Allobroges, Swiss, Piedmontese, and Savoyard supporters of the French Revolution
• Batavian Legion, Dutch supporters of the French Revolution in 1793
• Belgian Legion, Liégeois Legion, and Legion of Belgians and Liégeois: Belgian volunteers fighting on the side of the Republicans in the French Revolution
• Irish Legion, a French battalion established in 1803 for a future invasion of Ireland
• King's German Legion, British units of expatriate German personnel that fought against the French during the Napoleonic Wars
• La Legion Noire, a military unit of the French Revolutionary Army
• Polish Legions, Polish units in the service of Napoleonic France

  19th century

• British Legion, a British provincial regiment that served in the American Revolutionary War, 1777–1782
• British Legions, foreign volunteer units, established in 1819, who fought against Spain in South America's independence wars

  Other uses

• British German Legion, a group of German soldiers recruited to fight for Britain in the Crimean War, 1855–1856
• Greek Legion, a Septinsular Republic unit active between 1805 and 1807, taking part in the War of the Third Coalition and the Russo-Turkish War
• Royal Foreign Legion, infantry corps of mostly German mercenaries forming part of the restored French Bourbon army in 1815, renamed the Hohenlohe Regiment after 1821
• British Legion, officially the Auxiliary Legion, a British military force sent to Spain to support the Liberals and Queen Isabella II against the Carlists in the First Carlist War
• Academic Legion, a revolutionary students' group in Vienna in 1848
• Academic Legion, Polish nationalist students at the University of Lviv in 1848
• Greek Volunteer Legion, helping Russia in the Crimean War
• International Legion, a military force formed by Garibaldi in 1860 during the wars of Italian unification
• * The British Legion British contingent of the above
• Nauvoo Legion, a significant militia in early Mormon history
• List of American Civil War legions, both Confederate and Union
• Guelphic Legion, Hanoverian paramilitary unit supporting George V, deposed king of Hanover, from 1866 to 1870

  20th century

World War I

• Czechoslovak Legions, Czech and Slovak volunteer forces fighting on the the Allied Powers side
• French Armenian Legion, part of the French Army; also involved in the Franco-Turkish War of 1918–21
• Georgian Legion, a unit of the German Army recruited from Georgians
• Infantry Regiment of the Academic Legion, formed by volunteer Polish students in 1918, later taken into the regular Polish Army
• Italian Legione Redenta, an Italian military formation that participated in the Siberian Intervention during the Russian Civil War
• Jewish Legion, in the British Army at Gallipoli and Palestine
• Polish Legion in Finland, fighting for the Finns against the Russians
• Polish Legions in World War I, part of the Austro-Hungarian Army
• Puławy Legion, a Polish formation that was part of the Imperial Russian Army
• Legion of Ukrainian Sich Riflemen, a corps of the Austro-Hungarian Army

  Interwar period

• 2nd Legions Infantry Division, elite unite of the Polish Army, mostly composed of veterans of the Polish Legions in World War I
• British Legion Volunteer Police Force, a short-lived police force established in response to the outcome of the Munich Agreement in September 1938

  World War II

• Armenian or Armenische Legion, name given to the 812th Armenian Battalion of the German Army, made up largely of Armenian Red Army prisoners of war
• , made up largely of Azerbaijani Red Army prisoners of war
• Blue Legion, Spanish volunteers fighting against the Soviet Union on the Eastern Front
• Condor Legion, a unit of "volunteers" from the German Luftwaffe serving with the Nationalists during the Spanish Civil War
• Crna Legija, the name given to the 1st and 5th Croatian Ustaše Brigades
• Croatian Legion
• Croatian Air Force Legion
• Croatian Naval Legion
• Czechoslovak Legion in Poland, 1939
• Estonian Legion, a unit in the Waffen SS created in 1942, mainly consisting of Estonian soldiers
• Flemish Legion, recruited among Dutch-speaking volunteers from German-occupied Belgium, notably from Flanders.
• , a pro-Nazi Vichy French unit
• Legion of French Volunteers Against Bolshevism, pro-Nazi French
• Georgian Legion, a unit of the German army recruited from Georgians
• Indische Legion, also known as the Free India Legion or Tiger Legion, an Indian unit raised in 1941 and attached to the German Army
• Latvian Legion, a formation of the Waffen-SS created in 1943 and consisting primarily of ethnic Latvians
• Legion of St. George, the original name of the British Free Corps
• Ostlegionen, conscripts and volunteers from the occupied eastern territories recruited into the German Army
• La Légion Tricolore, a pro-Nazi French unit which was absorbed into the LVF after six months
• Volga Tatar Legion, one of several units formed by the Wehrmacht out of Soviet prisoners of war according to their ethnicity
• Walloon Legion, recruited among French-speaking volunteers from German-occupied Belgium.

  Other

• Arab Legion , the regular army of Transjordan, predecessor of the present Jordanian Army
• Foreign legion
• * French Foreign Legion, a unit of the French Army mainly composed of foreigners wishing to fight for France
• Polish Legions, eleven units at different times between the 18th and 20th centuries
• Spanish Legion, an elite unit of the Spanish Army