The Southern Illinois Roller Gremlins (SIRG, or So Ill Roller Gremlins) is a women's flat track roller derby league based in Marion, Illinois.

So Ill is a member of the Women's Flat Track Derby Association (WFTDA).

[1] The league was founded in June 2009 by a group of women from the area and So Ill Roller Girls had their first public scrimmage in December 2009, and their first official home bout in April 2010.

[2] It was accepted into the Women's Flat Track Derby Association Apprentice Program in January 2011,[3] and became a full member of the WFTDA in January 2012.

play at The Pavilion of the city of Marion, and their regular bouting season runs from March until November.