Carl Allan Serlachius (Särkilahti since 1935; 21 March 1870 Porvoo – 10 December 1935, Helsinki[1]) was a Finnish lawyer, a professor and a politician.
He was also the member of the Helsinki City Council between 1912 and 1914 and the Finnish Party MP during the Second Russification period of 1913 to 1916.
After the collapse of the fall of the Czarist regime, Professor Serlachius, representing the Finnish Party, was elected as senator to the Oskari Tokoi's cabinet and its successor cabinet of E. N. Setälä as the head of the Civilian Bureau until 27 November 1917.
After that, he acted as a chargé d'affaires of the newly independent Republic of Finland and later as special envoy and full minister to Oslo, Norway between 1918 and 1919.
He was a negotiator of the Treaty of Peace between Austria-Hungary and Finland signed in Vienna on 29 May 1918.