On 2 February 1900, Gustave Charpentier’s opera Louise premièred at Paris’s Opéra-Comique. Set in contemporary Montmartre, the work was discussed ubiquitously by its earliest critics as réaliste (translatable as both ‘realistic’ and ‘realist’) – a tendency that has continued in more recent musicological writing. In this article, I focus on Louise and discourse around it in order to re-examine the complex relationship between opera and realism. After sketching the terms of the opera’s reception to assess the case for understanding it as a ‘realist’ work, I position the opera in relation to theoretical conceptualizations of realism in other art forms. I then present two music examples to explore how Louise might not only resonate with existing understandings of late nineteenth-century French realism, but also expand or disrupt them. Ultimately, this article ponders the possibility that the act of listening might shape its own distinct form of realism.