It was not immediately clear if Fonda has an attorney who could comment on the arrest.
She and 15 other activists were charged with unlawfully demonstrating and "crowding [and] obstructing", according to the United States Capitol Police.
She wrote on her website: 'I can no longer stand by and let our elected officials ignore - and even worse - empower - the industries that are destroying our planet for profit.
"She read the read the [Intergovernmental Panel on Climate Change] report and she realized that the crisis was barreling straight at us, like a train", Fonda said, "and looked around and people weren't behaving appropriately".
Earlier Friday, Fonda appeared on D.C.'s WUSA 9 to talk about climate change.
"We have to be sure that the crisis that is climate change remains front and center like a ticking time bomb", she told WUSA9. Amid the protest, Fonda was arrested, handcuffed and placed in a police van, video posted to social media shows. "We don't have very much time, and it's really urgent".
"Inspired by Greta and the youth climate strikes as well as Reverend Barber's Moral Mondays and Randall Robinson's often daily anti-apartheid protests, I've moved to Washington, D.C.to be closer to the epicenter of the fight for our climate", she proclaimed.
The actress previously took a stand against the Vietnam War, for which some nicknamed "Hanoi Jane".
"I feel that I understand a little bit - this is a man who was traumatized as a child by his father, who had a mother that didn't protect him", she told the outlet.
"I do not know Mr. Giuliani's motives for attacking me", she says.