Albert Francis Blakeslee (November 9, 1874 – November 16, 1954) was an American botanist. He is best known for his research on the poisonous jimsonweed plant and the sexuality of fungi. He was the brother of the Far East scholar George Hubbard Blakeslee.

Albert Francis Blakeslee was born on November 9, 1874, in Geneseo, New York, to Augusta Miranda Hubbard Blakeslee and Francis Durbin Blakeslee, a Methodist minister.

Blakeslee attended Wesleyan University, graduating in 1896. At Wesleyan, Blakeslee played several sports and won academic prizes in mathematics and chemistry.

He received a master's degree from Harvard University in 1900 and a doctorate in 1904. He also studied at the University of Halle-Wittenberg in Germany from 1904 to 1906.

After graduating from Wesleyan, Blakeslee taught at the Montpelier Seminary in Vermont, as well as at the East Greenwich Academy.

His first professorship was at the Connecticut Agricultural College, now known as the University of Connecticut. He was hired by the Carnegie Institution in 1915, eventually becoming its director.

In 1941, Blakeslee retired from the Carnegie Institution and returned to academia, accepting a professorship at Smith College. He would go on to direct the Smith College Genetics Experimentation Station.

At Smith, he performed his research on jimsonweed. Blakeslee used the jimsonweed plant as a model organism for his genetic research. His experiments included using colchicine to achieve an increase in the number of chromosomes, which opened up a new field of research, creating artificial polyploids and aneuploids, and studying the phenotypic effects of polyploidy and of individual chromosomes.