Hullo is a village on the fourth largest island of Estonia, Vormsi, in Lääne County, Estonia. It is the administrative centre of Vormsi Parish. The population estimate of Hullo is 245 as of January 1, 2010. Island inhabitants date back to the 13th century. During most of its history the island was inhabited by Estonian Swedes ("rannarootslased" in Estonian or "coastal Swedes" in English), whose population reached 3,000 before World War II. During the war, nearly all of Vormsi's population, including Hullo's; were evacuated to Sweden.