St Mary's Old Convent Chapel is a category 1 historic building in Ponsonby, built in 1865–1866.

[1] St Mary's Old Convent Chapel was built for the Sisters of Mercy in 1865–1866 on land purchased by Bishop Jean-Baptiste Pompallier in 1853.

[1] The chapel was central to the convent life and also to the students of St Mary's College, which was constructed in 1864 on the site.

[3] The wooden chapel is cruciform with a steeply pitched roof and a central spire.

[1] The interior was laid out according to the needs of the religious order, rather than as a parish church, resulting in two rows of stalls made of kauri timber on both sides of the nave facing towards each other, across the central aisle.