Diamond Lil is a daily comic strip published by Creators syndicate and created by Paws, Inc. writer and artist Brett Koth about the life of Lillian Bilious, "a feisty 75-year-old widow" in the fictional town of Turkey Knuckle, Indiana. It has been running since 2010.

The character is named after a diamond anniversary (75 years), and because she is "one of the hardest substances known to man". Strips regularly feature her blunt and forthright opinions.