However, it's important to note that surnames can be found in different cultures and countries. While Portuguese is the most likely origin, it's possible that the DeCosta surname could have originated in other regions with Portuguese influence, such as:
* Brazil: Brazil has a large Portuguese population and many Portuguese surnames are common there.
* Spain: The Spanish language and culture have strong ties to Portuguese, and the surname DeCosta might be found in Spain as well.
* Other countries with Portuguese diaspora: The DeCosta surname could also be found in countries with significant Portuguese diaspora communities, such as Angola, Mozambique, and Cape Verde.
To determine the exact origin of a specific individual with the surname DeCosta, you would need to research their family history and genealogical records.