The name "Maine" comes from the fact that the state is on mainland, as opposed to part of the many surrounding islands. This nautical theory for the origin of Maine's name is the most prevalent, although there have been competing beliefs throughout the years. Scholars give the "mainland" theory the most credence, but there is no absolute certainty on the matter.
In 1622, King Charles of England granted a charter over what later became known as Maine to Sir Ferdinando Gorges and Captain John Mason. During his time in the royal navy, Mason served in the Orkney Islands, whose chief island is called Mainland. Historians suspect this served as inspiration for the state's eventual name.
First, however, Mason gave the province the names of New Hampshire, Laconia and New Somerset. The last one was particularly disliked by King Charles, so Mason finally wrote in the 1639 charter that the colony would thereafter be known as "Mayne." The name was fixed in 1665, when the king's commissioners ordered that in all official records from then on, the colony be registered as the "Province of Maine." Nevertheless, residents continued to argue over the name until 1819, a year before Maine achieved statehood.
A popular but academically rejected theory is that Mason chose the name Maine in honor of King Charles' wife, who was supposedly the owner of the French province of Maine. The historical record disproves that the queen had any such association with France.