Saima Rauha Maria Harmaja (May 8, 1913, Helsinki – April 21, 1937) was a Finnish poet and writer. She is known for her tragic life and early death, which are reflected in her sensitive poems. She came from a prominent family; her maternal grandfather was Arvid Genetz. She wrote four collections of poetry.
At the age of 15, Harmaja contracted the lung disease tuberculosis. There were good seasons and bad seasons, and in April 1937 she died at the age of 23. She is buried in the Hietaniemi Cemetery in Helsinki. Saima Harmaja kept a diary, which was published posthumously.
A literary club, Saima Harmaja Society, was founded in her memory.