BoltBus was an intercity bus common carrier and a division of Greyhound Lines that operated from March 2008 until July 2021 in the northeast and western United States and British Columbia, Canada.

At least one ticket on every bus was randomly sold for $1, excluding "handling charges". The $1 fare was the basis for its slogan "Bolt for a Buck".

In the northeast, BoltBus provided service between New York City and South Station Bus Terminal in Boston, Union Station in Washington, D.C., Penn Station in Baltimore, the Greenbelt Metro station in Greenbelt, Maryland, Penn Station in Newark, 30th Street Station in Philadelphia, and the Cherry Hill Mall in Cherry Hill, New Jersey. On the west coast, BoltBus service was offered in Oregon, Washington, and British Columbia, Canada. Service was available between International District/Chinatown station in Seattle and Portland, Pacific Central Station in Vancouver, Bellingham, Albany, and Eugene.

The BoltBus branding incorporated a thunderbolt logo similar to the one used by the British Union of Fascists, but the company claimed that the resemblance was purely coincidental.

When ticketed, passengers were assigned to a boarding group (S, A, B & C). Passengers who purchased their tickets earlier or were members of the company's loyalty program or had special needs got an earlier boarding group assignment.

In March 2008, facing competition from Chinatown bus lines in the northeast, Greyhound and Peter Pan Bus Lines partnered to launch BoltBus as a lower-cost brand.

The first route was between New York City and Washington, D.C., launched on March 27, 2008, followed by a route between New York City and Philadelphia launched on April 10, 2008, and between New York City and Boston launched on April 24, 2008.

That year, the company was named one of America's hottest brands by Ad Age.