Albert Levan (8 March 1905 – 28 March 1998) was a Swedish botanist and geneticist.

Albert Levan is best known today for co-authoring the report in 1956 that humans had forty-six chromosomes (instead of forty-eight, as previously believed). This epochal discovery was made by Joe Hin Tjio in Levan's laboratory.^[1]

Originally specialising in plant cytology, Levan later turned to the similarities in the chromosome structure of cancer cells and errors introduced to plant cells via chemical or radioactive elements. These studies later led to examination of chromosomes in animal cells.

In 1953, a lab mistake involving mixing HeLa cells with the wrong liquid led Joe Hin Tjio and Albert Levan to develop better techniques for staining and counting chromosomes. It allowed researchers for the first time to see and count each chromosome clearly in the HeLa cells with which they were working. They were the first to show that humans have 23 pairs of chromosomes rather than 24, as was previously believed. This was important for the study of developmental disorders, such as Down syndrome, that involve the number of chromosomes.^[2]

Levan was elected a member of the Royal Swedish Academy of Sciences in 1967.

Levan was cited by professor Bryan Sykes in the book Adam's Curse: A Future Without Men.^[3]