Karl Johan Fjermeros (29 September 1885 - 8 October 1972) was a Norwegian politician for the Liberal Party.
He was born in Høvåg.
He was elected to the Norwegian Parliament from Vest-Agder in 1945, but was not re-elected in 1949.
Fjermeros was a member of the executive committee of Oddernes municipality council in the periods 1936 - 1937, 1922 - 1925 and 1925 - 1928, and then served as mayor from 1928 to 1941 as well as briefly in 1945. In 1945 he was also briefly chairman of Vest-Agder county council. He was also acting County Governor of Vest-Agder from May to June 1945.
Outside politics he worked as a school teacher from 1908. In 1945 he was promoted to school inspector; from 1947 to 1965 he was the regional school director.