Mary Esther Murtfeldt (6 August 1839, New York City – 23 February 1913, Kirkwood) was an American entomologist, botanist, botanical collector, writer and editor.

She undertook research on the life histories of insects, describing several species new to science and wrote extensively on entomology.

[1] She grew up in Rockford, Illinois but lived most of her adult life with her family in Kirkwood, Missouri.

[5] This interest was encouraged by the then Missouri state entomologist Charles Valentine Riley who lived with the Murtfeldt family around 1870.

[1] From 1896 She was employed at the St Louis Republic, becoming the staff contributor in botany and entomology, and editing the journal Farm Progress.