Maria Mikhailovna Manaseina, née Korkunova (Мария Михайловна Манасеина; 1841 – 17 March 1903), also known as Marie de Manacéïne, was a Russian physician who published a number of books on fatigue and sleep. In 1872, she is supposed to have delivered experimental evidence for the cell-free alcoholic fermentation. Eduard Buchner was later awarded a Nobel Prize for the discovery of that process.
Manaseina was a disciple of Ivan Tarkhanov. In her monograph Sleep she observed that the brain is in an active state during sleep. She cited dreams as "evidence of an ongoing psychic life of sleep generated by the brain". An English translation appeared in 1897 as Sleep: Its Physiology, Pathology, Hygiene, and Psychology.
Manaseina's father was historian Mikhail Korkunov, and legal philosopher Nikolai Korkunov was her brother. Her second husband Vyacheslav Manassein was a well-known physiologist. After their separation Manassein married Fyodor Dostoyevsky's niece.