Carl Ludvig Engel or Johann Carl Ludwig Engel (3 July 1778 – 14 May 1840) was a German architect whose most noted work can be found in Helsinki, which he helped rebuild. His works include most of the buildings around the capital's monumental centre, the Senate Square and the buildings surrounding it. The buildings are Helsinki Cathedral, The Senate (now the Palace of the Council of State), the Helsinki City Hall, and the library and the main building of Helsinki University.