Sigma Delta (ΣΔ) is a collegiate sorority at Dartmouth College in Hanover, New Hampshire in the United States.

Women were not permitted to enroll at Dartmouth until 1972; the sorority provided a place where the college's coed students could meet.

[2] Its members made this decision to move away from "the patriarchal, puritanical and heteronormative conventions ingrained in sororities affiliated with national chapters".

[4] Sigma Delta's membership is open to all students who identify as female are gender noncoforming, and are nonbinary.

[5][1] In September 2010, Sigma Delta was charged with three counts of serving alcohol to minors during three incidents in the spring and fall of 2010.