Cross was a member of numerous academic associations, institutes, and societies. He was a fellow of the American Association for the Advancement of Science, British Association for the Advancement of Science, American Academy of Arts and Sciences, American Physical Society, Physical Society of France, American Institute of Electrical Engineers, and American Astronomical Society. In addition, Cross was President of the Appalachian Mountain Club in 1880 and the Chairman of the Rumford Committee of the American Academy of Arts and Sciences from 1897 to 1921.