According to parish register first permanent residents settled in the island in 1774. They probably inhabited the sheltered beach between mainland and Lilla Jussarö island. By the mid 1780´s a half-dozen families lived on the island.
Jussarö island made a great significance in the navigation at a time. First lighthouse was built on the island in 1891. But already before that there were official maritime piloting. Jussarö island was first mentioned around 1200-1300´s in danish route map which was included in so called King Valdemar´s Domesday book. The very first mention of a pilot in Jussarö island is from the year 1800.
Official pilot station
Jussarö island is mentioned as an pilot station in 1813. By the year 1839 two permanent and four deputy pilots operated from there. 1859 small guard house was built on the island and a little later a viewing tower was also built. At the turn of the century both were replaced by larger ones. 20 meters high light house was built at the south end of the island in 1891. Finland´s first unmanned light house was built in 1922 at nearby island Sundharu. Jussarö light house was shut down.
In 1814 magnetic presence was discovered in nearby island Leharun. 1834 promising ore deposit was found in the northern part of the Jussarö island by J. E. Westling. Ore mining was started the same year and by the 1837 14-18 men worked in the pit. 1839 mining was on hold but the mine was reopened in 1840 by Lars Gabriel von Haartman. He resigned 1859 and the mine was closed 1861.
Large-scale search of the ore deposits starts
In 1954 the finnish metal manufacturer Oy Vuoksenniska ab started a new search of ore deposits in Jussarö island. Ore mining was started in the summer 1959. The mine had a large role in the area of employment and development. People stopped fleeing the archipelago for a while. However before long the prices in the world market started going down and the costs were heading up which led to the closing of the mine again in 1967.
Coast Guard Station lands on the island
Due to the geographical situation of Jussarö island there has been multiple kind of military activities during the 1900`s. In the peace agreement signed with Soviet Union during WWII the small town called Hanko located west of Jussarö island was leased to Soviet Union for 30 years. Jussarö light house was blown up by Finnish Army and four cannons were placed on the island. Possession of the island remained at Finland. Finnish Coastal Battalion started maritime surveillance in the Jussarö island in 1962 together with Finnish Coast Guard.
Towards national park
The western half of the Jussarö island was included to Ekenäs Archipelago National Park at 1898 when the park was founded. The park is managed by Metsähallitus, State Forest Enterprise. During 2014-2015 Finland Defence Force handed over the administration of the east half of the island to Metsähallitus as well. So the long closed island has opened to public. Some restrictions of movement are however still valid.