LONDON — The Americans are coming.

Paul Giamatti is set to join the cast of hit Brit show “Downton Abbey” in the upcoming fourth series of the program, according to a report on TVLine on Monday.

He joins after fellow American Shirley MacLaine joined the program in series three.

Giamatti will play Harold Levinson, the playboy brother of Countess Cora (Elizabeth McGovern) in the Season Four finale, alongside MacLaine, who returns as Cora’s (and his) mother Martha.

Giamatti, who won an Emmy and a Golden Globe for his role in HBO’s “John Adams,” will join a number of new cast members who have signed up for the fourth series, including Tom Cullen, Nigel Harman and Julian Ovenden.

Season Four will air in the fall in Blighty and launch on PBS on January 5, 2014 in the U.S.