Jensen Beach is a census-designated place (CDP) in Martin County, Florida, United States. The population was 11,100 at the 2000 census. According to the United States Census Bureau, the CDP has a total area of 21.1 km² (8.1 mi²). 18.8 km² (7.2 mi²) of it is land and 2.3 km² (0.9 mi²) of it (10.82%) is water. There were 5,059 households out of which 23.8% had children under the age of 18 living with them, 47.2% were married couples living together, 8.8% had a female householder with no husband present, and 40.2% were non-families. 33.2% of all households were made up of individuals and 17.6% had someone living alone who was 65 years of age or older. The average household size was 2.19 and the average family size was 2.78.

As of the census of 2000, there were 11,100 people, 5,059 households, and 3,025 families residing in the CDP. The population density was 591.1/km² (1,531.8/mi²). There were 5,805 housing units at an average density of 309.1/km² (801.1/mi²). The racial makeup of the CDP was 95.80% White, 2.25% African American, 0.22% Native American, 0.47% Asian, 0.04% Pacific Islander, 0.37% from other races, and 0.86% from two or more races. Hispanic or Latino of any race were 2.77% of the population.