L. Jay Caldwell (June 19, 1871 – 1950) was an American football player and coach. He was the fourth head football coach at Colgate University and he held that position for two seasons, first in 1893 and then returning for 1895. His overall coaching record at Colgate was 7–2–2. He was born in Ephratah, New York in 1871. He married May Thorne on July 20, 1904 in Jamaica, New York. Caldwell later taught mathematics at a high school in Amsterdam, New York. In 1913, he was teaching at an Orange, New Jersey high school.