Dave Lehman was one of four children in a Pennsylvania Dutch farm family in Southern Lancaster County, PA. He came to wrestling relatively late competing for Solanco High School, but Roy Phillips, notable wrestling coach at F&M, took a chance and recruited him. While there, Lehman competed in freshman and varsity wrestling and football for all four seasons. He was a stalwart on the undefeated freshman wrestling team and had a successful varsity wrestling career competing at the 1967 EIWA Championships. Lehman, a Geology major, was awarded F&M's Alumni Junior Medal, which is given to the outstanding scholar-athlete in the junior class.

After graduating, Lehman served as a U.S. Army Artillery Officer in the Central Highlands of Vietnam. Upon completing his military service, he attended The University of Texas at Austin, where he earned a Ph.D. in Geological Sciences. After a successful career as an executive at ExxonMobil, he started up and subsequently sold three independent oil companies.

Lehman never forgot the role of wrestling in his education and in finding his chosen profession. His charitable contributions, especially to wrestling, are legendary. Among Lehman's most significant gifts is the $5 million endowment to Franklin & Marshall College's Division I wrestling program, for which the F&M Lehman Open—an annual tournament that draws more than 30 Division I teams from across the country—bears his name. Lehman extended his philanthropy to USA Women's Wrestling, becoming its largest financial supporter through a $1.5 million donation to advance the development of young American women wrestlers, helping propel the United States to the forefront of one of the fastest-growing sports worldwide. He is also the founder and major benefactor of Beat the Streets Lancaster, a wrestling and life skills program for underserved youth which reaches over 350 boys and girls in the Lancaster, PA area each year.

Lehman was inducted into the Pennsylvania Chapter of the National Wrestling Hall of Fame in 2018, and the Franklin & Marshall Hall of Fame in 2023. He currently lives in Denver, CO and has one daughter, two stepsons, and three grandchildren.