Keelung used to be called "Jilong", which means hencoop in Chinese.

In the late Ming Dynasty, the Japanese general Toyotomi Hideyoshi sent his troops to conquer Taiwan for the mines of brimstone in Keelung. His troops were forced to return when they encountered strong storms, but this somehow foretold a series of wars and battles in Keelung for the years to come.

In 1626, expeditions from Spain departed from Luzon and disembarked in Palm Island (present day Hoping Island) in Keelung. The Spanish built San Salvadore in the southwestern part of the island. In 1642, the Palm Island was occupied by the Dutch who changed the name of San Salvadore to Noort Hollant. In 1668, Cheng Ching, son of Cheng Cheng-kung, sent troops to fight against the Dutch and drove the Dutch out of the island. Before leaving, the Dutch engraved some words in a cave on Palm Island which was later named as "the Cave of Foreign Words".

Starting from mid Ching Dynasty, Keelung started to enjoy rapid development. This is mainly due to the abundant commodities including placer gold and high-quality coal, found in the drainage area of Keelung River.

In 1875, the court of the Ching Dynasty changed the old name "Jilong" into Keelung which means "rich and prosperous land".

In 1895, the first year of Japanese occupation, a five-phase construction of Keelung Harbor was initiated, which further stated the importance of Keelung Harbor for the economy and trade of Taiwan.

By 1916, the trade volume of Keelung Harbor has exceeded Danshuei and even Kaohsiung Harbor to become one of the major commercial harbors in Taiwan.

From 1924 to 1931, Keelung became a "City", which makes it the fourth largest city in Taiwan.

Unfortunately, the Pacific War broke out in 1941. As the main commissary and naval harbor, Keelung became the first target of American bombers and the harbor was nearly destroyed by the end of the war.

In 1945, after the handover of Taiwan from Japan, the City Government and the harbor bureau worked closely together to rebuild the city and the harbor. Thanks to the large population and prosperous economy in northern Taiwan, Keelung Harbor, with great equipment and facilities, plays an increasingly important role in econo-my. In fact, by 1984, the Harbor has become the 7th largest container harbor in the world.