One starting point for the Anthropocene, in which human industry has so profoundly altered the planet’s geosphere, is the invention of the steam engine in the late 18th century, a date roughly contemporaneous with the emergence of Romanticism. Through a focus on the Romantic concept of the sublime, a figure for a failure of representation or comprehension, this work of literary criticism unpacks that historical conjuncture and traces its implications forward, to the present moment of environmental crisis and digital mediation. Reading Romantic texts alongside more recent works – drawn from modernism, sci-fi, cli-fi, and ecopoetics – and pinpointing their parallel evocations of entanglement, immanence, hybridity, and ecological thinking, The Anthropocene Sublime shows how Romantic ideas about nature have shaped contemporary debates about ecology, as well as, more surprisingly, conceptions of technology, which are revealed to be embedded in Romantic thought and entangled with our perceptions of the natural world.