The section now known as Lyon County had settlers long before it became a county. Several original settlers, one, the Nichol's family, received land grants while this land was still part of Fincastle, Virginia, prior to 1776.

It has also been a part of the following counties: from 1776-1780, Kentucky County; 1780-1792, Lincoln County; 1792-1797, Logan County; 1797-1798, Christian County; 1798-1821, Livingston County, and 1821-18Caldwell County.

Land grants in what is now Lyon County were recorded in each of the above counties.

On January 18, 1821, Matthew Lyon started trying to establish Lyon County by dividing Caldwell County into two sections. The measure was put to the vote of the Caldwell County people and was voted down.

For thirty-three more years it remained part of Caldwell County. In 1854 a petition was circulated, an election held, Caldwell County divided, and the land became Lyon County on March 6, 1854, with Eddyville being chosen as the county seat.

Lyon County, the 102nd county in Kentucky to be established, was -carved out of the southeastern section of Caldwell County and named in honor of Crittenden Lyon.

The county is bounded on the north by Crittenden, northwest by Livingston, east by Caldwell, south by Trigg and west by Marshall.

It is bounded on the north by Livingston Creek and on the west by the Tennessee River. For a few miles the Tennessee and Cumberland Rivers winds centrally through the county forming the section known as "Between the Rivers."

The following information was copied from the first records in Deed Book "A" in Lyon County Court Clerk's office:

"The undersigned, a majority of the Commissioners appointed by the legislature of Kentucky to divide the County of Lyon into four districts for the election of Justices and Constables, which district shall also be election precincts, this day meet (sic) at the Counting room of R. L. & G. D. Cobb in the town of Eddyville, being first duly sworn faithfully and impartially to discharge our duties as such commissioners proceeds (sic) to lay off said County of Lyon into districts as follows:

District Number 1: Beginning on Cumberland River at the Mouth of Machen Branch running thence a distinct line to Rudy's Mill, on Eddy Creek, including the house of William B. Rudy, in said district, thence up Eddy Creek with the meanderings then off to the County Line, to the road leading from Princeton to Smithland, known as the Varmint Trace.