Emma of Altdorf, also known as Hemma (c. 803 – 31 January 876), a member of the Elder House of Welf, was Queen consort of East Francia by marriage to King Louis the German, from 843 until her death.

Emma's elder sister was Judith, who in February 819 married the Carolingian emperor Louis the Pious, and thereby became Queen consort of the Franks and Holy Roman Empress.

The wedding ceremony possibly[clarification needed] took place in Regensburg, where Louis the German resided as King of Bavaria subordinate to his father.

The Annales Bertiniani written by Archbishop Hincmar of Reims however reproach her for a pride which displeased the people of Italy.

She is also said to have inordinately favoured her son Carloman, designated heir of his father in Bavaria, which led to a revolt by his brothers.