Arlo Hanlin Hemphill (born October 7, 1971) is an American wilderness advocate. His educational background is in marine biology. Hemphill is a Fellow National of the Explorers Club and has been listed in Nature (Myers et al. 2000) as one of 100+ global biodiversity experts, credited for his expertise pertaining to the Greater Caribbean and the Tumbes-Chocó-Magdalena biodiversity hotspots. He is best known for his involvement in regional-scale ocean conservation and was a founding steering committee member of the Deep Sea Conservation Coalition, the Forum for the Conservation of the Patagonian Sea and Areas of Influence, and the Sargasso Sea Alliance.