On July 18, 1640, Daniel Patrick and Robert Feake, jointly purchased the land between the Asamuck and Tatomuck brooks, in the area now known as Old Greenwich, from Wiechquaesqueek Munsees living there for "twentie-five coates."

English settlers named their town after Queen Elizabeth's favorite town in England, which was Greenwich.

Modern "Greenwich Point" was natively called Monakeywaygo. Elizabeth Feake renamed it "Elizabeth's Neck" after purchasing the area with her husband and constructed the Feake-Ferris House (circa 1645) there, likely the first and oldest house in Greenwich.

The Dutch, based in Fort Amsterdam on the southern tip of Manhattan, sent armed soldiers to the Feakes and Patricks a few weeks after their arrival and forced them to acknowledge that their land lay within Dutch jurisdiction--a territory of the West India Company that was called New Netherland. The Dutch renamed Greenwich "Groenwits," to communicate its Dutch sovereignty, and the town served as the defended eastern border between New Netherland and New England.

During the American Revolution, General Israel Putnam made a daring escape from the British on February 26, 1779, in Greenwich. Although British forces captured and sacked the town, Putnam was able to warn Stamford. His famous ride is commemorated on the town seal, and the road that he used to escape is now named Putnam Avenue.

The railroad came to Greenwich in 1848, marking a dramatic improvement in transportation and bringing many immigrants who made Greenwich their home.

On the evening of October 30, 1975, Martha Moxley left with friends to participate in "mischief night", in which neighborhood youths would ring bells and pull pranks such as toilet papering houses. The next day, Moxley's body was found beneath a tree in her family's backyard. In 2002, a jury in Norwalk found Michael Skakel guilty of the crime. The case attracted worldwide publicity, as Skakel was the nephew of Ethel Skakel Kennedy, the widow of U.S. Senator Robert F. Kennedy.

Great Captain Island is the largest of a three-island group that also includes Little Captain and Wee Captain. The island is home to the Great Captain Island Light, a 19th-century lighthouse that was restored in 2009 and relit as a non-navigational aid in 2012. The island is open year round, with a ferry running during the summer.

According to local legend, a young Irish girl who worked in nearby Belle Haven fell in love with a handsome Greenwich piper who disappeared under mysterious circumstances. Shortly after his disappearance, the girl returned to Ireland and died of consumption. Witnesses claim to see the two outside of what is now the Bruce Museum at night. While ghostly voices call for the piper to enter the building and play for them, the couple make it clear to witnesses that they do not wish to enter.

Greenwich is the southernmost and westernmost town in Connecticut.