This talk traces the historical emergence of deadpan, a flat or neutral mode of performance that produces non-neutral responses, such as laughter. The definition of the “dead pan” as “playing a role with an expressionless face” was first recorded in a 1928 New York Times article, “Slang of Film Men,” in reference to Buster Keaton. But the gap between content and delivery as a central aspect of comedy developed earlier in a transatlantic context. In the United States, proto-deadpan performance styles emerged via the stage Yankee of the 1830s and the gravely delivered comic lectures of Artemus Ward in the 1860s. In England, the low comedian John Liston acted in a style that William Hazlitt described as “unconscious and involuntary,” Gilbert and Sullivan introduced the hyperlogical execution of an absurd premise in their comic operas, and Oscar Wilde asked actors in his comedies to de-theatricalize their performances. These unconscious, earnest, and understated styles of comic delivery present an alternative to conventional narratives of the shift from melodramatic to realist acting styles during the nineteenth century. By emphasizing the history and intentionality of comic impassivity, deadpan invites us to reconsider comedy’s relationship to social and aesthetic norms.