Evelyn Chrystalla "E. C." Pielou (February 20, 1924 – July 16, 2016) was a Canadian statistical ecologist.

Pielou studied at the University of London, where she obtained her bachelor's degree in botany in 1951 and her PhD in 1962.

Pielou was the second woman to win the Eminent Ecologist Award (1986) from the Ecological Society of America.

She lived in Comox, British Columbia, Canada, and wrote popular books on natural history until her death in July, 2016.

An outcome was not always one or the other, as it might have been different due to unforeseen circumstances or conditions initially thought as unimportant.