Operatic and theatrical historians in both Brazil and Portugal frequently mention that around the last quarter of the 18th century, Queen Maria I forbade women to perform on public stages in Portugal. However, it seems that the impresarios and owners of opera houses in colonial Brazil were unaware of this prohibition, since I have found several references to actresses performing in many of the permanent theatres at the end of the 18th century and the first decades of the 19th century. The great majority of these actresses were half-caste women. The most remarkable example is the case of soprano Joaquina Lapinha, prima donna of the Opera Nova in Rio de Janeiro, and probably the only native Luso-American singer to perform in a European theatre in the 18th century. This article considers the employment of actresses in the opera houses of São Paulo, Vila Rica, Rio de Janeiro, and Porto Alegre, showing how the impresarios of these public theatres managed to provide their companies with the necessary human resources.