1940 Southern Illinois Maroons football team

The 1940 Southern Illinois Maroons football team was an American football team that represented Southern Illinois Normal University (now known as Southern Illinois University Carbondale) in the Illinois Intercollegiate Athletic Conference (IIAC) during the 1940 college football season. Under second-year head coach Glenn Martin, the team compiled a 2–5–1 record.

Southern Illinois was ranked at No. 473 (out of 697 college football teams) in the final rankings under the Litkenhous Difference by Score system for 1940.

The team played its home games at McAndrew Stadium in Carbondale, Illinois.