According to the United States Census Bureau, the city has a total area of 7.1 square miles (18 km2), of which 6.7 square miles (17 km2) is land and 0.4 square miles (1.0 km2) (6.06%) is water. Casselberry features over 30 lakes and ponds, the largest being Lake Howell, the Triplet Chain of Lakes, Lake Kathryn, and Lake Concord.
Casselberry is located in the southern portion of Seminole County, Florida, approximately 10 miles north of downtown Orlando. Two major roadways, U.S. Highway 17-92 and State Road 436 intersect, connecting the City of Casselberry to all of Central Florida, including Interstate 4 which less than 5 miles away, and the Central Florida Greenway which is only 8 miles away. The City is engaged in development and redevelopment along the U.S. Highway 17-92 corridor, which presents mixed-use, retail and residential opportunities.
Diverse resort city – East-central Florida, about 25 miles from the Atlantic Coast. November, April, and March are the most pleasant months in Casselberry, while August and July are the least comfortable months.
Casselberry was originally part of unincorporated Fern Park. Residents decided to incorporate Casselberry as a tax-free town in 1940, to avoid property taxes. The town was reincorporated as a city in 1965, and property taxes were reinstated in 1976
At the 2010 U.S. Census, there were 26,241 people, 11,430 households, and 6,398 families residing in the city. The population density was 3,751.9 inhabitants per square mile (1,448.6/km2). There were 12,708 housing units. The median income for a household in the city was $44,807, and the median income for a family was $51,371. The per capita income for the city was $24,184. About 14.7% of the population were below the poverty line.
The City of Casselberry maintains 17 parks ranging from small neighborhood parks to large centers for recreation. Some of these parks include Branch Tree Park, Crystal Bowl Park, Dew Drop Park, and Forest Brook Park.
A diverse mix of fine retail establishments, restaurants, office and commercial space, housing at all price levels, as well as the Central Branch of the Seminole County Library and other Seminole County business offices are found in Casselberry.