De Alwis is a Sinhala surname. It is a corruption of the Portuguese surname Alves which was spread across Sri Lanka during the time of Portuguese rule of the island. Notable people with the surname include:
Anandatissa de Alwis, Sri Lankan politician
Guy de Alwis (1959–2013), Sri Lankan cricketer
James De Alwis (1823–?), Sri Lankan lawyer and writer
Lakshman de Alwis (1940–2008), Sri Lankan sprinter and athletics coach
Lanka de Alwis, Sri Lankan cricketer
Malathi de Alwis, Sri Lankan feminist
Prasantha Lal De Alwis, Sri Lankan lawyer
Premakeerthi de Alwis (1947–1989), Sri Lankan broadcaster, lyricist and television personality
Susantha De Alwis (died 2008), Sri Lankan diplomat
William de Alwis (1842–1916), Sri Lankan artist and entomologist
Lt.Colonel Sarath De Alwis (1965-1996), Sri Lankan Army Officer
Shavindra De Alwis (1991-), Sri Lankan Engineer, Researcher
