Siddhidas Mahaju (Nepal Bhasa: सिद्धिदास महाजु) (alternative name: Siddhidas Amatya) (15 October 1867 – 29 December 1929) was a Nepalese poet and one of the Four Pillars of Nepal Bhasa. He was at the forefront in the endeavour to revive literature in Nepal Bhasa that had become stagnant as a result of official suppression. He has been honored with the title Great Poet.