A Generaloberst ("colonel general") was the second-highest general officer rank in the German Reichswehr and Wehrmacht, the Austro-Hungarian Common Army, the East German National People's Army and in their respective police services. The rank was equal to a four-star full general but below a general field marshal. The rank was equivalent to a Generaladmiral in the Kriegsmarine until 1945 or to a Flottenadmiral in the Volksmarine until 1990. It was the highest ordinary military rank and the highest military rank awarded in peacetime; the higher rank of general field marshal was awarded only in wartime by the head of state. In general, a Generaloberst had the same privileges as a general field marshal.

A literal translation of Generaloberst would be "uppermost general", but it is often translated as "colonel-general" by analogy to Oberst, "colonel", such as in countries in which the rank was adopted like Russia (Russian: генерал-полковник, general-polkovnik). "Oberst" derives from the superlative form of Germanic ober (upper), cognate to English over and so "superior general" might be a more idiomatic rendering.

The rank was created in 1854, originally for Emperor William I, the Prince of Prussia, because members of the royal family were traditionally not promoted to the rank of field marshal and it was limited to wartime. In the 19th century, the rank was largely honorary and usually held only by members of the princely families or the Governor of Berlin. The regular promotion of professional officers to the grade did not begin until 1911.

Since the rank of Generalfeldmarschall was reserved for wartime promotions, the additional distinction of a "Colonel general with the rank of field marshal" (Generaloberst im Range eines Generalfeldmarschalls) was created. Such generals were entitled to wear three pips and a marshal's crossed batons on their shoulder boards, compared to the three pips of a Colonel General; however, this was changed to four pips in 1911.

Generaloberst was the second-highest general officer rank, below field marshal, in the Prussian Army as well as in the German Empire (1871–1918), the Weimar Republic (1921–1933), the Wehrmacht (which included the Luftwaffe, established in 1935) of Nazi Germany (1933–45) and the East German Nationale Volksarmee (1949–1991). As military ranks were often used for other uniformed services, the rank was also used by the Waffen-SS and the Ordnungspolizei of Nazi Germany and the Volkspolizei and Stasi of East Germany. In East Germany, the rank was junior to the general of the army (Armeegeneral), as well as to the briefly-extant and never-awarded rank of Marschall der DDR.