The Sentience Institute (SI) is an American interdisciplinary think tank that aims to expand humanity's moral circle.

The institute bills itself as, "an advocacy think tank researching and advising advocates on the most effective strategies to expand humanity's moral circle.

"[4] Its founders, Kelly Witwicki and Jacy Reese Anthis, were working at Sentience Politics, which was part of the Effective Altruism Foundation.

[2][7][8] The institute polled the views of American adults towards animal agriculture, most notably finding that 47% agreed with the statement, "I support a ban on slaughterhouses.

[14][15] In November 2018, Anthis, writing under the pen-name "Jacy Reese", published The End of Animal Farming, which summarizes and builds on most of the institute's research and communicates it with the general public.