The Ministry of Home Affairs said Huang Jing, a professor of US-China relations at the Lee Kuan Yew School of Public Policy, "knowingly interacted with intelligence organisations and agents of the foreign country" with the aim of bringing about a change in the direction of Singapore's foreign policy.
The ruling, which also applied to Huang's wife, Shirley Yang Xiuping, means that if the couple leave Singapore they will not be able to re-enter.
Neither of the couple was immediately available for comment.