PROVIDENCE — U.S. Sen. Lincoln D. Chafee has settled on his next move after his Senate term ends next month: he will join the faculty at Brown University as a teaching fellow.

Chafee, a 1975 Brown graduate with a degree in Classics, will teach a small seminar on an as-yet undecided topic for the university’s Thomas J. Watson Jr. Institute for International Studies.

Chafee, a Republican, was defeated in his bid for reelection by Democrat Sheldon Whitehouse in November. He said he had weighed a number of options for his next step, and the chance to teach at his alma mater jumped out at the former Warwick mayor.

“When I lost my first run for mayor, the phone didn’t ring when I lost that run. But after this event it was a little better … and certainly getting a call from the Watson Institute was the best call of all,” he said at a news conference yesterday at the institute.

Chafee will officially start on Jan. 7, and his first class will convene in late January. His appointment is for one semester, and he said he will reassess his options after that. He will be paid an undisclosed stipend.

The Watson Institute expects Chafee to lead group discussions among students and faculty, help write op-ed pieces, and try to bring visibility to the institute.

“The senator’s own experience really maps on to what we do here at the Watson Institute. We expect we’ll be enlisting the senator’s help to brainstorm about how we can get Brown research and Watson research out there,” said Geoffrey S. Kirkman, associate director of the institute.

“We are looking forward very much to having the senator help us think through how our research can make a bigger impact on the policy world out there,” he said.

Chafee would not comment on how this new endeavor might affect his political future, or whether he would remain with the Republican Party.

“I’m very happy to be coming here and avoiding those questions,” he said.

However, he did say that there was no truth to rumors that he would join his wife, Stephanie, in working at the Rhode Island Free Clinic in South Providence. Stephanie Chafee founded the clinic in 1999.

Brown’s newest professor will have an office in the Watson building on Thayer Street, and will hold office hours and act much as any other professor would.

“My understanding is that the senator will be here pretty much all the time,” Kirkman said.

Chafee said he is looking forward to the relative freedom of the academic world after his time in politics. “I do think that you are not as vulnerable when you’re in academics to push the boundaries a little bit further than you might be in politics,” he said.

For now, he said, he will turn his attention to figuring out what he wants to teach in his class.

Chafee, a member of the Senate Committee on Foreign Relations and the Committee on Homeland Security and Governmental Affairs, said that he may want to focus on issues in the Middle East.

He is also toying with the idea of writing a book about events he witnessed in the Senate.

“Having been in a box seat to the history that my term overlapped with, there might be a book there — and I don’t know if I can put that together, I really want to focus on this undergraduate study group. I just wonder if I can do it all.”

Chafee first entered public office as a Warwick city councilman in 1986 and won election as mayor of Warwick in 1992. He was appointed to succeed his father, John Chafee, in the Senate when the elder Chafee died in 1999. Lincoln Chafee was reelected in 2000.

The Watson Institute is an internationally known center for research and teaching in international affairs, focusing on global development, the environment and security issues.

Other recent visiting fellows include the former Brazilian President Fernando Henrique Cardoso, documentary filmmaker Eugene Jarecki, and former Burundian President Pierre Buyoya.