Pekka Elias Ervast, born 26 December 1875 in Helsinki, died 22 May 1934 in Helsinki, was a Finnish writer.
Ervast joined 1895 the Swedish theosophical society and started 1907 the Finnish theosophical society, Suomen Teosofinen Seura. He was chief secretatary there 1907-17 and editor for the journals Omatunto 1905-07 and Tietäjä 1908-20. When the society split up 1920 he founded Ruusu-Risti society and the journal Ruusu-Risti.
He got his inspiration from Leo Tolstoy.