The legendary singer had a front row seat for the 116th Congress, where Pelosi is expected to be elected House speaker. Among Pelosi's other guests include Mickey Hart of The Grateful Dead and Tim Gunn of "Project Runway."
Bennett tweeted a photo as he waited to enter the hall, writing, "Attending the swearing in ceremony for @NancyPelosi at the Capitol today."
Bennett and Pelosi go back a long time. She was in attendance in 2016 when Bennett had an 8-foot-tall statue made in his honor, which was unveiled in front of the Fairmont Hotel in San Francisco.
The two have also rubbed elbows at a number of ritzy events, including in 2014 at the 8th Annual Exploring The Arts Gala in New York City.
According to the Daily Mail, Bennett serenaded Pelosi on Wednesday night at a dinner hosted by Italy's ambassador to the United States.
Pelosi is poised to be elected Thursday as House speaker and is the only woman to ever hold the honor. She is also one of the few officials to ever regain the position, after previously serving as speaker from 2007-2011.