[8] Paleontological excavations in the area have unearthed the remains of numerous megafauna and other extinct species, including many herbivorous ungulates, artiodactyls (camelids, peccaries), perissodactyls (equids, tapirs), proboscideans (mammoths, mastodons), rodents (beaver, capybara, porcupine), tortoises and xenarthrans (armadillos, glyptodonts).

Later, more pressures on wildlife would have come from the arrival of the Clovis culture, who became prolific hunters with their distinct, fluted stone weaponry—including some of the earliest spears and arrowheads.

[14] Within a few years, all but a handful of these natives were dead from an epidemic that plagued the area after a British merchant ship ran aground.

[4] In April 1788, French botanist André Michaux traveled to Merritt Island, near Cape Canaveral, and spent five days looking at the local plants.

[15] In 1837, Fort Ann was constructed on the east coast of Merritt Island, near present-day Haulover Canal,[4] to protect the area against the local Seminoles.

[16] Merritt Island's recent history dates back to the mid-19th century, and centers on the growth of citrus, with an emphasis on the cultivation of oranges as well as pineapples.

[4] Freed slaves constructed small towns in the area after the Civil War, including Haulover, Clifton, and Shiloh.

Construction of a barge canal to the Intracoastal Waterway from the Atlantic Ocean (for power plant oil shipments) cut off the northern half of the island for many years.

The small towns on the island vanished with the coming of the Space Age, and now only live on in the names of streets and historic churches.

To the east it is separated by the Mosquito Lagoon and the Banana River from the barrier island on which Cape Canaveral and Cocoa Beach stand.

[4] Migratory birds join the more resident wildlife, including alligators, manatees, dolphins, sea turtles, bald eagles, ospreys, bobcats, and the elusive Florida panther.

A number of bald eagle nests are monitored atop power line poles along SR 3 within Kennedy Space Center.

[22] Merritt Island has or had 23 named communities,[4] all unincorporated, including: As of the 2020 United States census, there were 34,518 people, 13,790 households, and 8,600 families residing in the CDP.

Merritt Island is under the administrative care of the local county government, with water being handled by the neighboring city of Cocoa.

The county maintains operations for the sheriff's office, fire department, emergency medical services, and sewage systems.

[34] In 2005, the Florida House of Representatives codified all special acts and amendments, in regards to the Merritt Island Public Library District, under HB 1079.

SR 3, a four-lane highway, connects the Kennedy Space Center for workers from the more densely populated central and southern sections of the island.