Barbara Block is an American marine biologist and Charles & Elizabeth Prothro Professor of Biology in Marine Sciences at the Stanford University Hopkins Marine Station and a co-director of Stanford University's Tuna Research and Conservation Center, with the Monterey Bay Aquarium. She has published numerous bodies of work throughout her career in marine biology and chemistry, mainly focusing on the biology and chemistry of metabolism in different tuna and shark species. Additionally, she has helped develop two new types of electronic tags for large pelagic predators in order to track the migrations of large oceanic predator species.