|Locale central Maine|
Length 17.5 miles (28.2 km)
|Dates of operation 1886–1910|
|Track gauge 4 ft 8 ⁄2 in (1,435 mm) standard gauge|
The Sebasticook and Moosehead Railroad was a 19th-century Maine railroad which became the 20th century Harmony Branch of the Maine Central Railroad.
Monson, Maine, wanted a railroad to transport slate from their quarries to customers outside of Maine. The Monson and Athens Railroad built south from Monson, while the Sebasticook and Moosehead built north along the Sebasticook River from the Maine Central at Pittsfield. Track was completed from Pittsfield to Hartland in 1886, but the Monson end of the line stopped at a connection with the Bangor and Aroostook Railroad.
The seaport city of Wiscasset, Maine, began building the Wiscasset and Quebec Railroad inland in 1894 to increase trade through their harbor. Plans to include the Sebasticook and Moosehead as part of Wiscasset's route to Quebec were thwarted by inability to negotiate a crossing of the Maine Central line.
The Sebasticook and Moosehead had been extended as far as Mainstream by 1901 as an independent railroad receiving a share of revenues from traffic transferred to the Maine Central at Pittsfield. As part of the New England transportation monopoly organized by the New York, New Haven and Hartford Railroad, Maine Central leased the Sebasticook and Moosehead in 1910, purchased the company in 1911, and extended the line to Harmony in 1912. The line was known as Maine Central's Harmony Branch until 1966. It became known as the Hartland Branch when the extension from Hartland to Harmony was abandoned that year. The remaining Hartland Branch was abandoned in 1983.