The island was named Maio (Portuguese for "May") after its first sighting on May 1, 1460. The island was populated years later.
The inconclusive Battle of Maio was fought between British and French frigate squadrons off the island's southern coast on 23 January 1814 in the last stages of the Napoleonic Wars.
In the mid-18th century, salt was mined, the English used Vila do Maio to export its salt from its salt mines of the northwest to England and the Portuguese used Calheta to export its salt from Terras Salgadas to Portugal.
USS Yorktown was making its way to visit the nearby island of Santiago and some other African places, it visited Maio on September 4, instead, it sank around the island on September 6 making it one of the first American ships and likely its first sloop to sink in Cape Verdean waters and Maio island. The crew stayed for over a month until October 8 when the USS Dale arrived to pick up the crew and they were transferred to the Portsmouth.
Drought and famine like the rest of the country also struck Maio in the late 19th and the early and mid 20th centuries. Maio in its recent decades saw growth that the population is nearly 10,000 today.
The island covers an area of 269 km². The tallest mountain on the island (436 m) is on the east coast, in a mountain range named Monte Penoso. Terras Salgadas is a plain filled with salt, in the far north. The northernmost point on the island is Ponta Cais. Bays includes Galeão and Santana to the north and in the southeast is a lagoon named Cimidor. The island’s main town is Cidade do Maio (formerly Vila do Maio), also known as Porto Inglês, near which its airport, Maio Airport lies. Maio are one of six islands that have a surrounding islet or two, it is called Ilhéu Laje Branca. One of the notable beaches include the one west of the island capital, Morro and Praia Gonçalo.
Others places are:
The area to the north is predominantly shallow and the depths are down to around 100 meters below sea level in many areas, the highest is the João Valente Reef with a depth of only 16 meters The main Maio Seamount are nearly completely connected to other seamounts due to the shallow north, it connects the João Valente and Boa Vista seamounts to the north. Except for the shallow northern portion, southwest of the island has a depth of 1,000 km around halfway between the island and Santiago, the remainder especially the east over 10-20 km east are waters 3,000 km deep. These are part of the Cape Verde Rise. Surrounding seamounts in the east are Maio (or Lesser Maio, located about 90 km) and Noli seamounts (about 110 km).
As of 1832, the population was estimated at 2,500.
Most people in Maio are Roman Catholic.
The island prospered around salt collecting in its early days of colonialism, with a little agriculture and grazing.
There are two types of agriculture practiced in Maio, rain fed and irrigated. During the raining season products as corn, beans, pumpkins and melons are being cultivated. Products that farmers cultivate year round are sweet potato, cassava, papaya, fig, coconut and tamarind. Goats, cows, pigs, chickens and donkeys are common on the island. Few people own a horse. Scarcity of water is the biggest problem for the locals.
Fishery is important and abundant available. Tuna, sailfish and different coral fishes such as the coral hind are caught.
The economy is heavily supported by migrants who send money to their family on the island.
Tourism is slowly being developed.
Recently the northern part in the area between Morro and Cascabulho and parts of the southeast have become forested. Several forest areas exist on the island.
Endangered flora founded on the island include Asparagus squarrosus (Cape Verdean asparagus) and Verbascum capitis-viridis and endangered fauna include Tarentola maioensis.
Football is by far the most popular sport, but basketball and futsal along with water sports as surfing, diving and swimming are becoming more popular.