Dieterich (German pronunciation: [ˈdiːtəʁɪç]) is both a surname and a masculine German given name, a variant of Dietrich, itself the High German form of Theodoric. Notable people with the name include:

Surname:

• Albrecht Dieterich (1866–1908), German classical philologist and religious scholar
• Chris Dieterich (born 1958), American football player
• Heinz Dieterich (born 1943), German sociologist
• Helwig Dieterich (1601–1655), German physician
• Johann Christian Dieterich (1722–1800), German publisher
• Neil Dieterich (born 1943), American lawyer and politician
• William H. Dieterich (1876–1940), American politician from Illinois
• William H. Dieterich (judge) (1897–1964), American lawyer and judge from Wisconsin

Given name:

• Dieterich Buxtehude, (1637/39–1707), German-Danish organist and composer
• Dieterich Spahn, German-born American artist