Lewellen was born in Nadiad, India, to American missionaries and came to the United States when he was eight years old. With his parents moving quite a bit, he received his elementary school education in Ootacamund, India, Philadelphia and Albany. He attended high schools in Albany, Brooklyn, Bethlehem, located in the Albany area, and eventually graduated from Houghton in 1941. While at Bethlehem, Lewellen was a member of the 1940 varsity baseball team. After graduation, Lewellen enlisted in the United States Navy and served as a Lieutenant from 1942-1946 in the Pacific Theatre of World War II.
Following the war, he graduated from Houghton College with a Bachelor of Arts degree in history in 1949. While at Houghton, he ran track. Lewellen also did some undergraduate work at Hobart College and Columbia University. While earning a Master of Arts degree in physical education at the University of Kentucky in 1951, Lewellen studied under coaching great Coach Adolph Rupp. Lewellen additionally had further graduate work at St. Bonaventure University and Azusa Pacific College in California.