Johan Christian Sergei Fabritius, born May 29, 1890 in Moscow, died November 2, 1946 in Helsinki, was a Finnish military lieutenant colonel. He received his military training mainly in St. Petersburg and served during the First World War in the Russian engineering troops and participated in several battles in East Prussia, the Carpathians and Galicia. In 1917 he came to Finland and became chief of police in Raumo. In 1918, he commanded the White Guard on Åland and was later battalion commander in Satakunta.