Leon was born on September 17, 1945, to Alice McCollum and George Dillard. He was the bonus son of John Thompson and Ina 'Tobie' Dillard. Leon was predeceased by his parents, John and Alice Thompson, George and Ina Dillard, his sisters Rebecca and Lillie Thompson, a great-niece, Kiara Poole, and a great-nephew, LeFrance Vaughn.

Leon was baptized in the Woodman Hill Missionary Baptist Church, where he served as a junior usher in his teenage years. Leon graduated from East Flora High School, where he excelled at basketball and helped his team win the Gold Ball Championship. Immediately following graduation in 1965, Leon joined the United States Army. During his career in the Army, Leon was stationed in Okinawa, South Korea, Germany, and various US Bases. He earned his Associate's Degree while he was in the military. Leon's primary specialties were petroleum storage, transportation, and construction supervisor. His last assignment was in Niagara Falls, New York. Leon retired in 1986 after an honorable 21-year career. After retirement, Leon worked at the US Postal Service, the Army Corps of Engineers, and the Buffalo VA Hospital.

In 1991, Leon married Maria Puglia. They lived in Niagara Falls and Amherst, New York, before moving in 2003 to the warmer climate of Pembroke Pines, Florida. His favorite pastime was golf, and in Florida, he found the T&T club, a large group of like-minded men who enjoyed golfing twice a week at the many golf courses in the area.

Leon is survived by his wife Maria, stepdaughter Ariana, seven sisters, Cora Thompson (Madison, MS), Alice Lyle, Loistine (Raymond) Worthy, Annie (Richard) Grantham, Addie Green (Jackson, MS), Dessie Scott, and Mariea Thompson (Madison, MS)—and four brothers, Phillip (Leola) Thompson of Jackson, MS. Frank (Regina) Thompson, Canton, MS; Roy (Annie)Thompson and Wesley (Earnestine) Thompson, Jackson, MS. A host of nieces, nephews, great nieces and nephews, and great, great nieces and nephews, plus cousins, friends, and in-laws.