Felicia Keesing (born January 24, 1966) is an American ecologist and the David & Rosalie Rose Distinguished Chair of the Sciences, Mathematics, and Computing at Bard College in Annandale-on-Hudson, New York.

In Kenya, she has studied how the experimental absence of large mammals like giraffes and elephants affects savanna ecology, in particular the rodent community.

[4] She and Ostfeld also developed core ideas about the general relationship between biodiversity loss and the emergence and transmission of infectious diseases,[5] and a conceptual model of the effects of pulsed resources on ecological communities.

[6] From 2016 to 2021, she and Ostfeld co-directed the Tick Project, a study to test whether environmental interventions could prevent Lyme and other tick-borne diseases in residential neighborhoods of Dutchess County, New York.

[8] In 2009, she served on the steering committee for the Vision and Change[9] initiative to reform the teaching of undergraduate biology, and from 2012 to 2017, with funding from the Howard Hughes Medical Institute, she directed a project on science literacy for college students.