The Loneliest Whale: The Search for 52 is a 2021 American documentary film, directed, written, and produced by Joshua Zeman. Leonardo DiCaprio and Adrian Grenier serve as executive producers. The film follows a group of scientists in search of the 52-hertz whale, a whale which is believed to have spent its life in solitude, calling out at a frequency different from any other whale. It was commercially released in theaters and on video on demand by Bleecker Street on July 9, 2021.