Duck Key is a census-designated place and town in Monroe County, Florida, on an island of the same name in the middle Florida Keys. The CDP also includes the neighboring island of Conch Key. As of the 2000 census, the town had a total population of 443.
According to the United States Census Bureau, the CDP has a total area of 2.4 km² (0.9 mi²). 2.2 km² (0.9 mi²) of it is land and 0.1 km² (0.1 mi²) of it (5.49%) is water.
There is also an island called Duck Key that is located in North Port, Florida. Duck Key is a deed restricted community and is located at the end of Pan American Blvd.
There were 235 households out of which 8.9% had children under the age of 18 living with them, 56.6% were married couples living together, 3.0% had a female householder with no husband present, and 39.6% were non-families. 33.2% of all households were made up of individuals and 14.9% had someone living alone who was 65 years of age or older. The average household size was 1.89 and the average family size was 2.32.
In the CDP the population was spread out with 8.8% under the age of 18, 2.3% from 18 to 24, 20.8% from 25 to 44, 40.0% from 45 to 64, and 28.2% who were 65 years of age or older. The median age was 54 years. For every 100 females there were 101.4 males. For every 100 females age 18 and over, there were 101.0 males.
The median income for a household in the CDP was $39,125, and the median income for a family was $39,708. Males had a median income of $50,341 versus $26,429 for females. The per capita income for the CDP was $29,007. About 23.4% of families and 16.6% of the population were below the poverty line, including 6.9% of those under age 18 and 15.4% of those age 65 or over.
Duck Key is also home to Hawk's Cay resort and Marina which were constructed in the mid-1950s. The resort and multiple guest houses on the island have been popular with many celebrities including Arnold Schwarzenegger during the filming of "True Lies".
The Halliburton Company maintains a corporate retreat on Center Island. Another notable resident is New Jersey pen magnate Harold Zimmermann, who lives on Yacht Club Island.