Goi Domain (五井藩, Goi-han) was a feudal domain under the Tokugawa shogunate of the Edo period, located in, Kazusa Province (modern-day Chiba Prefecture), Japan.
It was ruled for the entirety of its history by a branch of the Arima clan.
Goi Domain was created on November 28, 1781, when Arima Ujiyoshi, the daimyō of Nishijo Domain in Ise Province relocated his jin'ya from Ise to Kazusa.
He died two years later, at the age of 23, and his successors likewise had unusually short lifespans.
As with most domains in the han system, Goi Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.