Hirado Domain (平戸藩), also known as Hirado-han, was a domain during the Edo period in Japan. It was located in Hizen Province, which is now part of Nagasaki Prefecture. The han system in Hirado was a political and economic concept that relied on surveys and projected agricultural yields, rather than land area, to define the domain. This system was distinct from the feudalism of the Western world.

Hizen Province was an old province of Japan in the area of the Saga and Nagasaki prefectures. It was sometimes called Hishū (肥州), with Higo Province. Hizen bordered on the provinces of Chikuzen and Chikugo. The province was included in Saikaidō. It did not include the regions of Tsushima and Iki that are now part of modern Nagasaki Prefecture.