The Maine Narrow Gauge Railroad Co. & Museum is located in Portland, Maine, United States. Based out of the Portland Company Marine Complex, the organization was founded in 1993 and contains a collection of rolling stock and artifacts from the 2 ft (610 mm) narrow gauge railways that ran in the state of Maine in the late 19th century and early 20th century.

The organization operates a 1½ mile long railroad that runs along the waterfront of Casco Bay and parallels Portland's Eastern Promenade. A variety of restored locomotives and coaches are used to run passenger services on the railroad.