Eck received her B.A. in Religious Studies from Smith College in 1967, and her M.A. in South Asian History from The School of Oriental and African Studies, University of London in 1968. In 1976 she received her Ph.D. from Harvard University in the Comparative Study of Religion.

Eck became interested in other religions, and Hinduism in particular, when she went to India at age 20 with the University of Wisconsin College Year in India program and studied at Banaras Hindu University. Since then, she has held many research fellowships for study and research in India.

Since 1991, Diana Eck has also turned her attention to the United States and has been heading a research team at Harvard University to explore the new religious diversity of the United States and its meaning for the American pluralist experiment. The Pluralism Project has developed an affiliation with many other colleges and universities across the country and around the world. In 1994, Diana Eck and the Pluralism Project published "World Religions in Boston, A Guide to Communities and Resources" which introduces the many religious traditions and communities in Boston, Massachusetts - from Native Americans, Christians, Jews, Muslims, Buddhists, Hindus, Sikhs, Jains, to Zoroastrians. In 1997, Diana Eck and the Pluralism Project published an educational multimedia CD Rom, "On Common Ground: World Religions in America" (Columbia University Press). This CD Rom received awards from Media & Methods, EdPress, and Educom.

In 2001, her book A New Religious America was published. It deals with the new religious diversity in the United States.

In 1998, Eck and Dorothy Austin became the first same-sex couple to be masters of Lowell House, one of the twelve undergraduate residences at Harvard.

In 1996, Prof. Eck was appointed to a U.S. State Department Advisory Committee on Religious Freedom Abroad, a twenty-member commission charged with advising the Secretary of State on enhancing and protecting religious freedom in the overall context of human rights.

In 1998, President William J. Clinton and the National Endowment for the Humanities awarded her for her work on American religious pluralism.

In 2002, Diana Eck received the Martin Marty Award for the Public Understanding of Religion from the American Academy of Religion

In 2003, Diana Eck received the Montana Humanities Award from the Governor of Montana

In 2007, Professor Eck was made a lifetime member of the Girl Scouts of America