Scotia Prince Cruises was a cruise ferry operator based in Maine which owned and operated the M/S Scotia Prince. This ferry operated across the Gulf of Maine between Portland, Maine, and Yarmouth, Nova Scotia, until the end of the 2004 sailing season.

The Portland-Yarmouth seasonal (summer only) ferry service was established in 1970 by European ferry operator Lion Ferry. The first vessel was the M/S Prince of Fundy which operated from 1970 to 1976. She was assisted on the route between 1973 and 1976 by the M/S Bolero. Between 1976 and 1981 the only vessel in use was the M/S Caribe.

Lion Ferry leased the International Marine Terminal from the City of Portland. At the City's request the original lease included a clause for bilateral "route protection" which prevented Lion from operating a route from any other New England port to Nova Scotia, and prevented the City from allowing another operator to sail to Nova Scotia during Lion's operating season. The City's facilities were used by other operators including cruise ships. Lion also used the Yarmouth Ferry Terminal in Nova Scotia which was owned by the federal Department of Transport, although Lion had to share its Yarmouth facility with Canadian National Railways which operated the MV Bluenose service to Bar Harbor, Maine.

From 1978 to 1982, CN Marine also operated the MV Marine Evangeline (ex-MS Duke of Yorkshire) between Yarmouth and another terminal owned by Canadian National Railways on the Portland waterfront.

The service was sold by Lion Ferry in 1982 to Baron Stig Leuhusen who established Prince of Fundy Cruises as a subsidiary of Panamanian-based Transworld Steamship Company. The vessel M/S Scotia Prince (ex-M/S Stena Olympica) was acquired and began service that season. In 1983, the other Yarmouth ferry operator, CN Marine, began using a sistership M/V Bluenose II (ex-M/S Stena Jutlandica) on its Bar Harbor crossing. Prince of Fundy Cruises had the Scotia Prince lengthened in 1987 for increased capacity, changing the visual similarities between both ships. Leuhusen died in 1996 and his estate listed the company for sale in 1999.

In August 2000 the company's shares were purchased by a group led by Matthew Hudson of Virginia. The company was renamed Scotia Prince Cruises. The Scotia Prince was re-flagged (Bahamas). The company upgraded the ship and onboard services in addition to other improvements made at the company. The service was repositioned from a transport provider to a transport and package vacation company. The service was marketed as a cruiseferry and destination in its own right.

In 1997, CN Marine's successor (government-owned and subsidized) Marine Atlantic Yarmouth-Bar Harbor service was privatized by the government and taken over, along with the M/V Bluenose, by Northumberland Ferries Limited which established a subsidiary service named Bay Ferries Limited. At the same time, the federal Department of Transport transferred operational responsibility of the Yarmouth ferry terminal to Bay Ferries. The Bluenose II was sold at the end of the 1997 season by Bay Ferries and the proceeds were used to purchase the high-speed catamaran ferry HSC INCAT 046, named The Cat. Service began the following summer in 1998 dropping the crossing time from 6 hours to 2.5 hours. A few years later, HSC INCAT 046 was replaced by a slightly larger ship, HSC The Cat, still referred to as The Cat.

During the winter of 2002–2003, Scotia Prince Cruises Ltd. inaugurated a service called the "Yucatan Express", using the M/S Scotia Prince on a route between Tampa, Florida, in the United States and Cancun, Quintana Roo, and Merida, Yucatán, in Mexico.