The earliest marked grave in Lemley Cemetery is that of Elizabeth Moore, dating to 1857, on part of a 160-acre tract settled by the Thomas B. Martin family in 1853 and patented to Martin by the state of Texas six years later. The cemetery appears in Parker County deed records by 1869, when Martin sold his property to John H. and Thomas J. Lemley, who had come to Texas from Illinois in the mid-1850s and eventually settled in Parker County. The cemetery on their property came to bear their name and was used over the years for family members, friends, and nearby settlers. Tombstones mark the graves of landowners Thomas Martin and George Lemley and others who lived and died in the area, many of them victims of the hardships of pioneer life on the Texas frontier. At least five Civil War veterans are buried there, and many graves are marked only with native rocks, making the cemetery an important reflection of the heritage of this part of Parker County.