"Rêveurs" are members of the unofficial fan club for The Night Circus.
The creation of the Rêveurs began with Herr Friedrick Thiessen, a clockmaker, who became devoted to the circus. Herr Thiessen wrote multiple articles and reviews praising the circus and exploring the many components which make up the remarkable spectacle. Over time, people who read the articles wrote back to Herr Thiessen, sharing his enthusiasm for the circus. This lead to Herr Thiessen becoming the unintentional leader of the Rêveurs.
The name "Rêveur" is in reference to that alternate title for the circus - Le Cirque Des Reves. "Rêveur" literally meaning "Dreamer".
Rêveurs distinguish themselves from everyone else due to their uniform: all black or white clothing, with a single red accent (such as a scarf).