According to the United States Census Bureau, the village has a total area of 9.2 square miles (23.9 km²), of which, 9.2 square miles (23.8 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.22%) is water.
There are 50 parks and 45 miles of bike paths/sidewalks.
There were 15,708 households out of which 42.7% had children under the age of 18 living with them, 66.0% were married couples living together, 6.6% had a female householder with no husband present, and 25.8% were non-families. 22.1% of all households were made up of individuals and 6.4% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.23.
In the village the population was spread out with 28.9% under the age of 18, 5.3% from 18 to 24, 32.2% from 25 to 44, 24.6% from 45 to 64, and 9.0% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 93.6 males. For every 100 females age 18 and over, there were 89.2 males.
The median income for a household in the village is $80,525, and the median income for a family is $92,583. Males have a median income of $63,107 versus $41,039 for females. The per capita income for the village is $39,794. 2.3% of the population and 1.3% of families are below the poverty line. Out of the total people living in poverty, 2.6% are under the age of 18 and 2.2% are 65 or older.
The first pioneers arrived in the Buffalo Grove area around 1834, and by the 1840s had established a small community.
The origin of the name "Buffalo Grove" is uncertain, but the traditional account is: "When the English, French, and Pottawatomi Indians were ranging through northeastern Illinois, so were the buffalo. The buffalo left the Wheeling woods in the morning and grazed their way diagonally to Long Grove. Noon found them in a grove of trees along the creek - drinking and resting. A buffalo skeleton was found beside the 'Buffalo Creek,' as it soon became called."
From early settlement to the 1950s, numerous dairy farms and cheese producers dotted the landscape. Througout most of the first half of the 1900's, Buffalo Grove served as a primary dairy producer for the Chicago area. The Weidner and Raupp families, along with other German Catholics, farmed in the region surrounding Saint Mary's Roman Catholic Church, just across the county line from the original development plat.
Buffalo Grove was incorporated as a village on March 7, 1958, with a population of 164.
Buffalo Grove slowly began to build homes and businesses. In the 1950's, Al Frank, a developer, built hundreds of homes along Buffalo Grove Road, west along Bernard Drive as far as the current Park District headquarters, formerly Louisa May Alcott School. By 1961, houses west of Buffalo Creek and the school were added as far west as Greenwood Courts North and South, north through neighborhoods including Cherrywood and Cottonwood Roads and south through White Pine Road. These earliest homes, in the Cook County section of the village, are sometimes referred to as "Old Buffalo Grove". Older housing stock is often surrounded by larger, newer houses, apartments and condominiums due to pockets of formerly undeveloped farmland being surrounded by housing. Over time, these so-called "holdout parcels" were sold and developed.
The fledgling village grew rapidly in the 1960s with the development of Ranch Mart Shopping Center, near the corner of Buffalo Grove Road and Dundee Road (State Route 68). In the late '60s, the center contained a grocery store (Jewel Foods), a dime store (Hornsby's), a dry cleaner, a shoe store, and a pharmacy (Mark Drugs). Nearby, on Dundee Road, stood a bowling alley (originally "The Rose Bowl," later, "Striker Lanes"). In 1970, the enclosed Buffalo Grove Mall, including a grocery store ("Elm Farms," a subsidiary of National Tea), a dime store ("Scott's" of the TG&Y chain), an ice cream shop ("Baskin & Robbins") and a Radio Shack, opened. Both these complexes have undergone significant physical renovations and tenant changes in the intervening years.
Throughout the 1960's and 1970's more homes and businesses came up. Rising taxes, along with rapidly increasing land values, encouraged farm famiilies to sell farms for residential and commercial development. By the early 1970's Buffalo Grove had approximately 15,000 residents. During this time the city also grew in physical size, annexing significant land from nearby unincorporated areas, particularly in nearby Lake County. In 1992, the United States Postal Service established a free-standing post office in the village, and in 1996, METRA opened commuter rail service to Chicago. In 2005, the village had upwards of 43,000 people in it.
Today, the village is largely developed. Approximately one-quarter of the village's land area is reserved for nature preserves and parks. The village continues trying to annex land of unincorporated Prairie View (Vernon Township), which is surrounded by Buffalo Grove. The village maintains its efforts to receive Arlington Club, a former golf course on which apartments and condominiums were built in the 1980s.
Four school districts and three high school districts serve Buffalo Grove. The majority of public high school students in Buffalo Grove live in the Cook county portion of Buffalo Grove attend Buffalo Grove High School. A smaller population of students residing in the Cook county portion of Buffalo Grove attend Wheeling High School. Those living in the Lake county portion of Buffalo Grove attend Adlai E. Stevenson High School.
Other districts and schools serving Buffalo Grove are:
Kildeer Countryside C C School District 96:
Lincolnshire-Prairie View School District 103:
Community Consolidated School District 21:
St. Mary School (Catholic Pre-school through 8th grade)