Lovisa Adelaïde Ehrnrooth (17 January 1826 – 31 May 1905) was a Finnish feminist and writer. Adelaïde Ehrnrooth was born in Nastola, one of the 16 children of an aristocratic family. She was born to , a hero of the Finnish War. John Casimir Ehrnrooth was her brother. Adelaïde Ehrnrooth never married, and dedicated her life to helping the women and the poor. Adelaïde Ehrnrooth proposed voting rights for women in 1869. Aside from her activist life and writing poetry, Adelaïde Ehrnrooth wrote travel accounts of her frequent journeys.