The Gaysin uezd was a county (uezd) of the Podolian Governorate of the Russian Empire, with its administrative centre in Gaysin (modern-day Haisyn). The area of the Gaysin uezd covered the area of modern-day Haisyn Raion.
The subcounties (volosts) of the Bratslav uezd in 1912 were as follows:
At the time of the Russian Empire Census on , the Gaysin uezd had a population of 248,142, including 123,305 men and 124,837 women. The majority of the population indicated Little Russian to be their mother tongue, with a significant Jewish speaking minority.