Population in 2003 was 1,438 but the town has been shrinking in size since the 1950's when the town reached its peak with 3000 inhabitants. The town grew up around the herring industry that was in much bloom in the 1940's and 1950's.
Today the town remains dependent on fishing industries although the herring is gone. The government of Iceland is attempting to reverse the population shrinking in the area by improving land transportation. Two road tunnels will be dug in the next decade to connect Siglufjörður to the neighbouring town of Ólafsfjörður and the region of Eyjafjörður. These tunnels will be totally 11 km in length.