Carl Otto Lenz (born 5 June 1930) is a German lawyer, member of the German Bundestag (1965–1984) for the CDU and Advocate General at the European Court of Justice (1984–1997).
Born in Berlin, Carl Otto Lenz is the son of the lawyer Otto Lenz (Secretary of the Federal Chancellery 1951–1953, member of the German Bundestag 1953–1957) and Marie Liese Pohl.
In 1959, he became Secretary of the Christian Democratic Group of the European Parliament in Luxembourg; From 1965 to 1984 he was a member of the German Bundestag, representing Bergstraße.
For many years he was a member of the Legal Affairs Committee, and he was its chairman from 1969 to 1980.
Lenz is also editor of a handbook and the author of numerous works concerning EC law.