"The town of Sulaiman Beg is under control of the combined forces of Iraqi army, Peshmerga (Kurdish force) and volunteers," the official told Xinhua.
The troops are still clearing the booby-trapped buildings and roadside bombs in the town, located some 90 km east of the provincial capital Tikrit, the official said.
The militants fled the town, with large areas of the province still under the control of the IS.
The recapture of Sulaiman Beg came a day after the combined security forces broke through to the town of Amerli, some 90 km east of Tikrit, as well as several nearby villages after more than two months of being captured by the IS.
The security forces, backed by thousands of Shia militiamen and Kurdish Peshmerga fighters, moved in to the town of Amerli under US and Iraqi air support, and were involved in fierce clashes with the militants.
Salahudin province is a predominantly Sunni province and its capital Tikrit, some 170 km north of Iraq's capital Baghdad, is the hometown of former president Saddam Hussein.