Remsenburg-Speonk is a census-designated place (CDP) located in the Town of Southampton, Suffolk County, New York, United States.

Most of the early residents came west from Southampton and Bridgehampton in the 1740s, building farms and clearing the forests of wood.

In the 1880s, duck farms thrived in Speonk, but few survived past the turn of the century.

The name Speonk was inspired by a Native American word meaning "high place".

An 1897 Long Island Rail Road catalog listed Speonk, noting that that name "certainly sounds like the call of a frog".