Nantucket LORAN-C transmitter was a LORAN-C transmitter at Siasconset, Massachusetts.

It was built in 1963 with a 625 ft tall mast radiator.

It operated in conjunction with the LORAN-A station on Nantucket from 1963 to 1981.

It was closed in 2010 when the United States discontinued the Loran system, and officially decommissioned on September 10.

[1] The tower was taken down in May 2013.