Columbia is comprised of 32.2 square miles, which includes 31.9 square miles of land and .3 square miles of water.

Columbia is served by six Howard Transit bus routes that connect it with neighboring areas such as Ellicott City, while several Maryland Transit Administration (MTA) routes provide access to and from both Washington and Baltimore. MTA weekday commuter bus service connects Columbia to the Washington Metro system. There are no rail stations within Columbia, although the Dorsey MARC Train station is served by Howard Transit buses.

Columbia has a number of major roadways that provide drivers with quick access to Baltimore, Washington, D.C. and Annapolis: U.S. Route 29, Interstate 95, MD 32, MD 108, MD 100, and MD 175.