Louis De Pui "Bucker" Vail (September 18, 1870 – December 16, 1948) was an American football player and coach. Vail played football and graduated from Germantown Academy. He attended the University of Pennsylvania, receiving both his A.B. and his LL.B. He was a member of Delta Phi Fraternity. Vail played football at Penn as a quarterback from 1889 to 1893. Vail also played baseball at Penn in 1891 and 1892.