The county is named in honor of Isaac Shelby, Governor of Kentucky from 1792 to 1796 and again from 1812 to 1816.

Shelby County is included in the Birmingham–Hoover, AL Metropolitan Statistical Area.

This long defunct settlement was located within the modern city limits of Pelham.

Shelby County was the home of an early inland waterway, the Coosa River, and it was also the location of a very early east–west railroad in Alabama that connected Atlanta, Georgia, with locations to its west.

Shelby County was also crossed by an early north–south railroad, the Louisville and Nashville Railroad, that connected Louisville, Nashville, Decatur, Birmingham, and Montgomery.

With the advent of the automobile and the truck, Shelby County was soon crossed from north to south by U.S. Highway 31, the major one that followed the same route as the Louisville and Nashville Railroad did.

Decades later, Shelby County was crossed by Interstate Highway 65.

Hence, an important ingredient in the eventual growth of Shelby County has been its ready access to modern systems of transportation.

Interstate 65 and U.S. Highway 31 have long provided strong connections between Shelby county and the more populous Jefferson County directly to its north, leading to suburban development in towns such as Pelham, Helena, Alabaster, and Chelsea.

However, large parts of Shelby County are much flatter, giving good land for farms and pastures.

[13] The population density was 283.9 inhabitants per square mile (109.6/km2) There were 89,060 housing units.

The largest self-identified ancestry groups in Shelby County were Of the 74,072 households 34.3% had children under the age of 18 living with them, 59.7% were married couples living together, 9.4% had a female householder with no husband present, and 27.5% were non-families.

The largest self-reported ancestry groups in Shelby County are: English (16.3%), Irish (13.3%), American (mostly English and Scots-Irish) (11.5%), German (11.0%), Italian (4.2%), Scots-Irish (4.2%) and Scottish (3.9%).

Between 1984 and 1992, the county saw a complete reversal from Democratic dominance to Republicans in control of all but a couple of offices.

It was not until the election of 2010, and specifically the results in Alabama House of Representatives District 42,[14] that Republicans held every partisan elected office with jurisdiction or residency (or both) in Shelby County.