Adjacent counties

Collier County is located at the southern end of Florida's Gulf Coast, and bounded by:

• Hendry County – north
• Broward County – east
• Miami-Dade County – southeast
• Monroe County – south
• Lee County – northwest

National protected areas

• Big Cypress National Preserve (part)
• Everglades National Park (part)
• Florida Panther National Wildlife Refuge
• Ten Thousand Islands National Wildlife Refuge

Major highways

• Interstate 75
• U.S. Route 41
• State Road 29
• State Road 84
• State Road 951

2000 census

As of the census^[14] of 2000, 251,377 people, 102,973 households, and 71,257 families resided in the county. The population density was 124 people per square mile (48 people/km²). The 144,536 housing units had an average density of 71 per square mile (27/km²).

As of 2000^[update], its racial makeup was 86.06% White, 4.54% was African American, 0.29% Native American, 0.62% Asian, 6.25% from other races, and 2.23% from two or more races. Hispanics or Latinos (of any race) accounted for 19.61%. Primary languages spoken were 75.3% English, 17.8% Spanish, 2.3% French Creole, and 1.2% German.

In 2000, of the 102,973 households, 22.7% had children under 18 living with them, 58.1% were married couples living together, 7.2% had a female householder with no husband present, and 30.8% were not families. About 24.5% of all households were made up of individuals, and 11.9% had someone living alone who was 65 or older. The average household size was 2.39, and the average family size was 2.79.

The county's population distribution was 19.9% under 18, 6.6% from 18 to 24, 24.6% from 25 to 44, 24.5% from 45 to 64, and 24.5% who were 65 or older. The median age was 44.1 years, higher that the U.S. average. For every 100 females, there were 100.30 males. For every 100 females 18 and over, there were 99.20 males.

The median income for a household in the county was $48,289, and for a family was $54,816. Males had a median income of $32,639 versus $26,371 for females. The per capita income for the county was $31,195. About 6.6% of families and 10.3% of the population were below the poverty line, including 16.2% of those under age 18 and 4.3% of those age 65 or over.

2010 census

The county continues to experience significant growth and is becoming increasingly diverse. As of the 2010 census, the county's population had increased by 27.9% to 321,520, over the 2000 census. As of the 2010 census, 83.85% of the population was non-Hispanic Whites, 25.9% was Latino or Hispanic, 6.6% was African American, and 1.1% was Asian.^[15] As of the 2010 census, the greatest source of population growth in the county since the 2000 census came from the Latino or Hispanic population, which grew from 49,296 (19.6%) to 83,177 (25.9% ). In terms of ancestry, 37.9% were English, 9.9% were Irish, 9.1% were "American", 3.2% were Italian and 3.1% were German.^[16]

2020 census

As of the 2020 United States census, 375,752 people, 140,578 households, and 97,279 families resided in the county.

Voter registration

According to the Secretary of State's office, Republicans comprise a majority of registered voters in Collier County. It is also one of the handful of counties where independents outnumber Democrats among registrants. The county is part of a long-established Republican stronghold in southwestern coastal Florida; the last Democrat to win the county was Adlai Stevenson II in 1952.^[20] The last Democratic governor to carry the county was Reubin Askew in 1974 and the last Democratic senator to do so was Bob Graham in 1992; six years later, the county was one of four to back the then-Republican candidate, Charlie Crist.

All voter information is as of September 30, 2022^[update], and provided by Collier County Supervisor of Elections Office.^[21]

Statewide elections

Cities

• Everglades City
• Marco Island
• Naples

Census-designated places

Community development districts

• Fiddler's Creek District #1
• Fiddler's Creek District #2

Other unincorporated communities