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.

Adelaïde Ehrnrooth never married, and dedicated her life to helping the women and the poor.

She was also active in the Union Kvinnosaksförening (Women's Cause Association) in 1884 and the years after 1892 until her death in Helsinki.

[1] Aside from her activist life and writing poetry, Adelaïde Ehrnrooth wrote travel accounts of her frequent journeys.