The Comet, officially the Central Midlands Regional Transit Authority, is the agency responsible for operating mass transit in the greater Columbia area including Cayce, West Columbia, Forest Acres, Arcadia Lakes, Springdale, Lexington  and the St. Andrews area. COMET operates express shuttles, as well as bus service serving Columbia and its immediate suburbs. The authority was established in October 2002 after SCANA released ownership of public transportation back to the city of Columbia. Since 2003, COMET has provided transportation for more than 2 million passengers, has expanded route services, and introduced 43 new ADA accessible buses offering a safer, more comfortable means of transportation. CMRTA has also added 10 natural gas powered buses to the fleet. COMET went under a name change and rebranding project in 2013. Before then, the system was called the Columbia Metropolitan Rapid Transit Association or "CMRTA".
The Central Midlands Council of Governments is in the process of investigating the potential for rail transit in the region. Routes into downtown Columbia originating from Camden, Newberry, and Batesburg-Leesville are in consideration, as is a potential line between Columbia and Charlotte connecting the two mainlines of the future Southeastern High Speed Rail Corridor.
Roads and highways
Columbia's central location between the population centers of South Carolina has made it a transportation focal point with three interstate highways and one interstate spur.
- I-26 Interstate 26 travels from northwest to southeast and connects Columbia to the other two major population centers of South Carolina: the Greenville-Spartanburg area in the northwestern part of the state and North Charleston – Charleston area in the southeastern part of the state. It also serves the nearby towns and suburbs of Chapin, Irmo, Harbison, Gaston, and Swansea.
- I-20 Interstate 20 travels from west to east and connects Columbia to Atlanta and Augusta in the west and Florence in the east. It serves the nearby towns and suburbs of Pelion, Lexington, West Columbia, the Sandhill region, Pontiac, Elgin, Lugoff, and Camden. Interstate 20 is also used by travelers heading to Myrtle Beach, although the interstate's eastern terminus is in Florence.
- I-77 (William Earle Berne Beltway) Interstate 77 begins at a junction with Interstate 26 south of Columbia and travels north to Rock Hill and Charlotte. This interstate also provides direct access to Fort Jackson, the U.S. Army's largest training base and one of Columbia's largest employers. It serves the nearby towns and suburbs of Forest Acres, Gadsden, and Blythewood.
- I-126 Interstate 126 begins downtown at Elmwood Avenue and travels west towards Interstate 26 and Interstate 20. It provides access to Riverbanks Zoo.
The city and its surroundings are served by Columbia Metropolitan Airport (IATA: CAE, ICAO: KCAE, FAA LID: CAE). The airport itself is serviced by American Eagle, Delta, and United Express airlines. In addition, the city is also served by the much smaller Jim Hamilton–L.B. Owens Airport (IATA: CUB, ICAO: KCUB, FAA LID: CUB) located in the Rosewood neighborhood. It serves as the county airport for Richland County and offers general aviation.
The city is served daily by Amtrak station, with the Silver Star trains connecting Columbia with New York City, Washington, DC, Savannah, Jacksonville, Orlando, Tampa, and Miami. The station is located at 850 Pulaski St.
Until 1959 the Southern Railway's Skyland Special (Asheville, North Carolina - Jacksonville, Florida) made a stop in Columbia. Until 1966 the Southern Railway's Augusta Special went north from Columbia to New York City via Charlotte, North Carolina and went west to Augusta, Georgia's Union Station, where passengers could make connections to Georgia Railroad trains to Atlanta, Georgia. The Charleston branch of the Southern's Carolina Special made a stop in Columbia.
Greyhound Lines formerly operated a station on Gervais Street, in the eastern part of downtown, providing Columbia with intercity bus transportation. The station relocated to 710 Buckner Road in February 2015.
MegaBus began operations in Columbia in 2015. There routes include stops in Atlanta, Fayetteville, North Carolina, Richmond, Virginia, Washington, DC, and New York City, New York. The station is located on Sumter Street.