Group of Houses of the Santa Casa de Misericórdia, Colonial monument complex in João Pessoa, Brazil.

The Church of Our Lady of Mercy is a Catholic church in the Historic Center of João Pessoa, the only surviving church in the plain (chão) style in Paraíba. Its Mannerist facade has a central body topped by a smooth triangular pediment with a cross, two small windows and an oculus, and a straight belfry with two arched windows on the left. Inside are a single shallow nave, side chapels, side altars and a lateral gallery.

Duarte Gomes da Silveira built the church with his own funds on the site of a primitive chapel, and it is considered the first church of Paraíba. He established the Morgado do Salvador do Mundo around 1639, and the church later served as mother church during the Dutch invasion of 1635 and when the main parish needed repairs. IPHAN listed it on 25 April 1938.

The church belonged to the Santa Casa de Misericórdia, which used it not only for religious offices but also for care of the sick, children and prisoners, and for the burial of slaves and condemned people. The arch between the presbytery and the rest of the church carries the emblem of the corners of the old Portuguese crown, and the Chapel of the Savior of the World has another emblem resembling Spanish coins from the time of Philip II.

The church stands in the Historic Center of João Pessoa, at the corner of the Santa Casa complex, and is listed by IPHAN since 25 April 1938. Look for the stone wheel of the exposed on the main facade and the straight belfry with two arched windows on the left. The side chapel of the Savior of the World sits set back from the facade, with a two-leaf door.

The church keeps the tomb of its founder, Duarte Gomes da Silveira, and his wife in the Morgado do Salvador do Mundo chapel, on the left side of the nave. The opposite side chapel holds an ossuary. The building is the only surviving example of the plain "estilo chão" in Paraíba.