Is there life in the clouds of Venus? How could Indigenous burning practices stave off catastrophic bushfires? What do horseshoe bats, raccoon dogs, and pet cats have to do with the global pandemic? Science writing tells the stories of life and human endeavour in all its marvellous—often messy—complexity. Now in its eleventh year—and with a foreword by Australia's Chief Scientist, the renowned physicist Cathy Foley—The Best Australian Science Writing 2021 is a collection that showcases the nation's best science writing. New voices join prominent science writers and journalists, taking us to the depths of the ocean, the fuels of the future, and to the Ryugu asteroid and back. The collection also brings us straight to the heart of complex ethical dilemmas and the calamitous crises challenging scientists and writers alike. Includes the shortlisted entries for the 2021 UNSW Press Bragg Prize and the 2020 UNSW Press Bragg Student Prize winning essay.