The Guelphic Legion (German: Welfenlegion) was a Hanoverian paramilitary unit maintained at the expense of George V, deposed king of Hanover, from 1866 to 1870. In the autumn of 1866, a large number of Hanoverian soldiers left Hanover for the Netherlands at the behest of King George V and his newly established court at Hietzing near Vienna. After being raised as a sizable force, in 1867 the Legion migrated to Switzerland, where its numbers swelled to 700.
George V, who never abandoned his claim to the Hanoverian throne, maintained the Legion at his own expense while in exile in France. In February 1868, the Guelphic Legion moved from Switzerland to France, at the same time that George V and his wife celebrated their silver wedding anniversary. In 1869, the Prussian lower chamber passed a law sequestering the funds of the former King of Hanover in retaliation against his support of the Guelphic Legion.
The Guelphic Legion was formally dissolved on April 15, 1870. Each of the 1,400 legionnaires received 400 francs upon discharge and additional traveling expenses as needed. Many returned to Hanover, but some migrated to America or to other parts of Europe.