The county was named for Isaac Shelby, a hero of the King's Mountain Battle during the Revolutionary War. Also, he was the first governor of the state of Kentucky, and had refused election to a second term as governor in order to fight the Indian wars. The first courthouse was fashioned of logs, and was located at Shelbyville, long since deserted, however, believed to have been located within the modern-day city of Pelham. It was selected as the county seat in 1820 and the county's first courthouse was built by Thomas Amis Rogers, Alabama's first Secretary of State, who, along with his neighbor George Phillips, represented the county in the state's first Constitutional Convention in 1819. Judge Joab Lawler was the first judge to preside in the courthouse. The Shelbyville courthouse, built at a cost of $53, was used until 1826, when the decision was made to move the courthouse and the county seat.
In 1826 the location of the courthouse was moved to an old school building in Columbia, located in the central part of Shelby County. However, an act of the Legislature changed its name to Columbiana on January 13, 1832, and the county seat was then permanently located at Columbiana. The "Petition to Incorporate Columbiana" is found in Will Book "K" dated August 10, 1853 and was signed by A.A. Sterrett, Wm. M. Allen, B.O. Nabors, N.B. Mardis, R.H. Brasher, John T. McComic, A.M. Elliott, E.G. Lawley, J.A. Teague, Samuel Leeper, S. Brasher, H.V. Nabors, D.W. Caldwell, J.L. Wilson, D.N. McClanahan, A.J. Donus, A. Parnell, Jos. Roper, Jno. Baker, and L.F. Elliott. In 1854, the decision was made to build another courthouse, which is today referred to as the "old courthouse." In 1982, the Shelby County Historical Society and Shelby County Museum and Archives moved in, and is still there today.
Construction began on the current stone courthouse in 1905 at a then-price of $300,000. The cornerstone ceremony was held April 5, 1906. An addition was completed in 1954. It received a multi-million dollar renovation in the early 1990's. On March 4, 2006 the contents were removed from the cornerstone and placed on display at the Shelby County Museum & Archives. The "100-year celebration and cornerstone ceremony" was held June 24, 2006. On July 15, 1983 the first "satellite license office" was opened in Pelham, Alabama. The second "satellite license office" was opened Monday, July 17, 2006 in the Inverness Corners shopping center on U.S. 280.
The first authentic records regarding Shelby County date from 1820 when early white settlers held their lands by virtue of what was known as Squatter Sovereignty, and titles to their holdings were not granted by the government until 1821. The fear of an attack by marauding bands of Indians caused the settlers to be on alert lest their possessions be stolen or burned. However, when government Land Offices were opened, farmers and others who had established themselves on choice plots of ground rushed in to apply for and receive title.
Most of the first settlers came from South Carolina, Tennessee, and Kentucky and returned to this region after the victorious Battle of Horseshoe Bend in 1814. They brought their families and their household goods, traveling chiefly by pack horse, to remain in this section of Alabama. The first settlements in the area were at Montevallo, then known as Wilson's Hill, Harpersville, Wilsonville, and Shelbyville. As indicated in the 1820 Shelby County census records, two years after it was created, the county contained 2,492 people; 2,044 whites and 448 Negroes. Shelby County has experienced a 210 percent increase in population between 1970 and 1990. In 1992, the population was 107,261 in a land area of 646 square miles, and average of 166 per square mile.