Holmberg IX is a dwarf irregular galaxy and a satellite galaxy of M81, located in the constellation of Ursa Major. It is a Magellanic-type galaxy, similar to the Small Magellanic Cloud, neighbour galaxy to the Milky Way galaxy. The galaxy is named after Erik Holmberg who first described it, though it was originally discovered by Sidney van den Bergh in 1959. Based on the observed age distribution of stars it contains, 20% of its stellar mass formed within the last 200 Myr, making it the youngest nearby galaxy. It is also home to one of two yellow supergiant eclipsing binary systems designated Holmberg IX V1.