Aino Krohn Kallas (August 2, 1878 – November 9, 1956) was a prominent Finnish - Estonian author. Her novellas are considered to be among the finest pieces of Finnish literature. Kallas is also known for her love affair with the legendary poet Eino Leino.

Aino was the daughter of Julius Krohn, a nationally known Finnish scientist and fennoman, and the sister of Kaarle Krohn. Her father was also one of the first people to publish poetry written in Finnish language. In 1900 Aino married Oskar Kallas (b. 1868), an Estonian scholar, doctor of folklore and later diplomat. The couple lived in Saint Petersburg and had five children. In 1904 they moved to Tartu, Estonia. Aino became interested in the history and culture of her new homeland and she joined Noor-Eesti, a sociocultural society which campaigned for the independence of Estonia. Although she continued writing in Finnish, she often wrote about Estonian subjects. She lived in London from 1922 to 1934, while her husband was Estonia's ambassador to the United Kingdom. She published her diaries for the period 1897 - 1931 in the 1950s.

A recurring theme in Aino's novellas is what she termed "the slaying Eros", a love that often leads to death, especially prominent in her trilogy of Sudenmorsian (The Wolf's Bride), Reigin Pappi (The Pastor of Reigi), and Barbara von Tisenhusen. The language of her most famous story, Sudenmorsian, a werewolf story set in 17th century Hiiumaa is rich with archaic, Romantic, colorful prose, something of a Kallas trademark. A collection of her short stories was published in English under the title "The White Ship", with a foreword by John Galsworthy in 1924.