The Ruins of Saint Paul's (Chinese: 大三巴牌坊; Portuguese: Ruínas de São Paulo) are the remnants of a 17th-century Catholic religious complex in Santo António, Macau.

In 2005, they were officially listed as part of the Historic Centre of Macau, a UNESCO World Heritage Site.

[2]: 122  Likely influenced by Japanese Christian craftsmen who worked on it, the ruins of St. Paul's include carvings with heterodox images that draw from Asian traditions, including Mary stepping on a seven-headed hydra, described in accompanying Chinese characters as "Holy Mother tramples the heads of the dragon".

[3] Resisting calls for the dangerously leaning structure to be demolished, from 1990 to 1995, the ruins were excavated under the auspices of the Instituto Cultural de Macau to study its historic past.

Numerous religious artifacts were also found together with the relics of the Chinese Christian martyrs and the monastic clergy, including the founder of the Jesuit college in Macau, Father Alessandro Valignano.