Railway companies of New Hampshire

List of railway companies in the American state of New Hampshire.

Companies based in the United States

 * Conrail (CR), freight and passenger

Companies based outside of the United States

 * Canadian National Railway (CN), freight

Regional railways

 * St Lawrence & Atlantic Railroad (SLR, SLQ), freight

Shortline and terminal railways

 * Green Mountain Railroad (GMRC), freight and passenger
 * Milford-Bennington Railroad (MBR), freight
 * New England Southern Railroad (NES), freight
 * New Hampshire Central Railroad (NHCR), freight
 * New Hampshire Northcoast Corporation (NHN), freight
 * Plymouth & Lincoln Railroad (PLL), freight and passenger

Defunct railways
Years shown here refer to the period in which a given company operated in New Hampshire; they may have existed elsewhere before or after these years.