The play begins in 1640, in a Hall of the Hotel de Bourgogne that is being used as a theater. Theater-goers enter to see the play La Clorise by Balthasar Baro. These attendees include a royal soldier and a Musketeer, who fence, and lackeys, who gamble. The audience also includes a guardsman, who tries to kiss a girl selling flowers; pages, who dance and set up to fish for wigs; and a thief who teaches students to steal. Marquises, citizens, and other vendors also enter.

Lignière introduces Christian de Neuvillette—who is joining the Guards—to Cuigy and Brissaille. These men and two marquises name other entering theater patrons for Christian’s benefit. Christian asks Lignière about a particular woman (Roxane, but he doesn’t know her name yet) who has not entered her box. Lignière gets some wine and introduces Christian to Ragueneau, a pastry chef. Ragueneau and Lignière discuss giving pastries in exchange for poetry. Others join in when they begin praising Cyrano for his wit and swordplay and discuss his large nose.

Roxane enters her box, and the men praise her beauty. Lignière tells Christian her name, her status as single, and how another married man with her (Comte de Guiche) wants her to marry one of his friends, Valvert.