Diedrich is both a masculine German given name and a German surname. Notable people with the name include:

• Diedrich Bader (born 1966), American actor, voice actor and comedian
• Diedrich A. Bohlen (1827–1890), German-born American architect
• Diedrich Diederichsen (born 1957), German writer, music journalist and cultural critic
• Diedrich Henne (1834–1913), German-born Australian botanist
• Diedrich Hermann Westermann (1875–1956), German missionary, Africanist and linguist
• Diedrich Téllez (born 1984), Nicaraguan footballer
• Diedrich Uhlhorn (1764–1837), German engineer
• Diedrich Wattenberg (1909–1996), German astronomer
• Diedrich Willers Jr. (1833–1908), American politician

• Friedrich Diedrich (1935–2015), German Roman Catholic theologian
• John Diedrich, Australian actor, director and producer

• Diedrich Coffee, an American coffee company
• Diedrick, given name and surname