First St. Mary's Roman Catholic Church, Warwick, Heritage Catholic church in Warwick, Australia.

First St. Mary's Roman Catholic Church occupies a prominent position on Palmerin Street with Gothic Revival architecture featuring detailed stonework and traditional design elements. The building shows sturdy construction with tall walls and carefully crafted decorative features throughout its exterior.

Warwick became a separate parish in 1862, with Dr John Cani as first priest; land in Palmerin Street was secured by 1863. Brisbane architect Benjamin Backhouse designed the Gothic church, built 1863–1865 by contractor CA Doran from Sidling Quarries stone for about £1500, and Bishop Quinn opened it on 23 August 1865 as St Mary of the Assumption. Father Horan added the transepts and chancel by 1894; after the second St Mary's opened in 1926 the building was deconsecrated.

Deconsecrated in 1926 after the Second St Mary's Church opened, the building has since served as a community meeting hall and store. It also housed the Catholic primary school from its earliest days, partitioned with calico screens to separate the sanctuary from the teaching area and later to divide the classrooms.

The former church stands inside the grounds of the Catholic primary school on Palmerin Street, so access follows school and community-hall use rather than parish mass times. The building is a community meeting hall and store, not a consecrated church; the Second St Mary's, further north on the same block, serves the parish.

The sandstone came from the Sidling Quarries, a small group of quarries in Warwick. The church was damaged by a severe thunderstorm before it opened on 23 August 1865, and the original building was only the nave, with side doors opening straight into the body of the church rather than through porches.