In December 2006, Weller starred as architect Frank Lloyd Wright at Chicago's Goodman Theatre in Frank's Home, a new play by Richard Nelson.
In 2006, Weller joined the cast of 24 as terrorist collaborator Christopher Henderson. Weller received a "cheer" in TV Guide's "Cheers & Jeers" section for his performance.
On June 24, 2006, on his 59th birthday, Weller married his longtime girlfriend, actress Shari Stowe, at the Santa Maria Assunta church in Positano, Italy. Among the guests attending the wedding were Carrie Fisher and Marg Helgenberger.