The Roman Catholics from the Mangalore Diocese (erstwile South Canara district), and their descendents are generally known as Mangalorean Catholics. The diocese falls on the southwestern coast of India. At present, it comprises of the whole civil districts of Dakshina Kannada and Udupi in Karnataka state, and Kasaragod taluk of Kerala state. This region was collectively referred as South Canara during the British regime, prior to the States Reorganisation Act (1956). In 1526, after Portuguese shipping arrived in Mangalore, while the number of local converts slowly increased, an immigration of Christians from Goa to South Canara started on a large scale, in the second half of the 16th century. These Goan immigrants were reluctant to learn the local languages of South Canara. They continued to speak Konkani, the language which they brought from Goa, and the local Christians had to learn Konkani if they wanted to converse with these people.

After migration, the skilled Goan Catholic agriculturists were offered various land grants by the native Bednore rulers of South Canara. Most migrants came from the lower economic strata, who had been left out of Government and economic jobs, and their lands confiscated due to heavy taxation, under the Portuguese in Goa. As a consequence of the wealth and privilege which these Goan migrants enjoyed in Mangalore, they began feeling superior to their landless brethren in Goa. They no longer identified to their caste-based community in Goa. With the release from the captivity at Seringapatam from 1784-1799 came a sense of purpose, a sense of common identity, among the Mangalorean Catholics who had hitherto considered themselves mainly as an extension of the larger Goan Catholic community. In its rebirth, for the first time a separate Mangalorean Catholic cultural identity was formed. Even after their captivity at Seringapatam, where many died, were killed, or forcibly converted to Islam, the British employment on ships, their prosperity under the British and Italian Jesuit regimes, their migration and employment to Bombay, Persian Gulf Arab States, and the Anglosphere enabled the community to restore their identity.