Illa is a surname, Catalan ''Island''. Notable people with the surname include:
*
Esteban Terradas i Illa
Esteban Terrades i Illa (15 September 1883, in Barcelona – 9 May 1950, in Madrid) also known as Esteve Terradas, was a Spanish mathematician, scientist and engineer. He researched and taught widely in the fields of mathematics and the physica ...
(1883–1950), Spanish mathematician, scientist, and engineer
*
Rolando Illa (1880–1937), Cuban-Argentine chess player
*
Salvador Illa
Salvador Illa Roca (born 5 May 1966) is a Spanish politician who served as Minister of Health of Spain from 2020 to 2021. He has been the Secretary for Organization of the Socialists' Party of Catalonia since 2016, and the candidate for the p ...
(born 1966), Spanish politician
{{surname, Illa
Catalan-language surnames