The sit-in Tuesday involved dozens protesting the Keystone XL pipeline. It would go through Montana, South Dakota, Nebraska, Kansas, Oklahoma and Texas to refineries in Houston and Port Arthur, Texas.
Before she was arrested, Hannah told The Associated Press the protesters want to be free from dependence on fossil fuels. The group calls for clean energy investments instead. Hannah says they hope President Barack Obama will not bow to oil lobbyists.
Hannah sat down on the sidewalk near the White House and refused orders from U.S. Park Police to move.
She has been arrested in the past for environmental causes.