According to the United States Census Bureau, the city has a total area of 17.7 square miles (45.9 km²), of which, 15.9 square miles (41.2 km²) of it is land and 1.8 square miles (4.7 km²) of it (10.16%) is water mostly due to the location of the Ross Barnett Reservoir.
There were 9,267 households out of which 28.8% had children under the age of 18 living with them, 40.7% were married couples living together, 10.4% had a female householder with no husband present, and 45.8% were non-families. 38.6% of all households were made up of individuals and 6.5% had someone living alone who was 65 years of age or older. The average household size was 2.15 and the average family size was 2.90.
In the city the population was spread out with 23.4% under the age of 18, 10.2% from 18 to 24, 40.3% from 25 to 44, 17.8% from 45 to 64, and 8.2% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 89.9 males. For every 100 females age 18 and over, there were 86.7 males.
The median incomes for a household in the city was $43,066, and the median income for a family was $59,249. Males had a median income of $40,632 versus $29,634 for females. The per capita income for the city was $28,704. About 5.5% of families and 7.4% of the population were below the poverty line, including 9.2% of those under age 18 and 5.6% of those age 65 or over.
In 1853, James B. Yellowley founded the community of Yellowley's Crossing (later named Jessamine, after his wife). Two Chicago developers, Edward Treakle and Gordon Nichols, purchased the land from Yellowley and founded Highland Colony. They laid out a city which they named Ridgeland and enticed settlers from the Northern US to move south. Farming thrived with pears and strawberries among the chief crops.