Jack "Sid" Siedlecki (pronounced /sɪdˈlɛki/ sid-LEK-ee; born July 23, 1951) is an American football coach. He was a head coach in college football for 21 years for Worcester Polytechnic Institute (1988–1992), Amherst College (1993–1996) and Yale University (1997–2008). He led his teams to championships in the Ivy League (Yale in 1999 and 2006), the Freedom Football Conference (Worcester Tech in 1992), and the New England Small College Athletic Conference (Amherst in 1996). He was selected as the American Football Coaches Association District I Coach of the Year after the 2006 season.