Alexander William Evans (May 17, 1868 – December 6, 1959) was a botanist, bryologist, and mycologist that specialized in the flora of Connecticut.

Born in Buffalo, New York on May 17, 1868, Evan's family moved to New Haven, Connecticut after the death of his father.

After a two-year internship at the Yale-New Haven Hospital, he went to the University of Berlin to briefly study botany under Leopold Kny.

Later in life, Evans became enraptured by Yasuhiko Asahina's work on the microchemical methods of lichen, which he believed he could apply to taxonomy.

A list of Evans' publications on lichens is given in Mason Hale's 1960 summary of his lichenological work.