Illinois bundleflower (IBF; Desmanthus illinoensis) is a warm-season perennial legume native to the central plains of the United States and has potential as both a forage and grain crop. The objective of this research was to evaluate the potential of IBF seeds as a feed ingredient in broiler starter diets. One-day-old broiler chicks were fed 1 of 4 isocaloric and isonitrogenous experimental diets containing 0, 5, 10, or 15% IBF seed. Illinois Bundleflower seed is a high-protein (31.5% CP) feed ingredient with a Lys:Met similar to that of soybean meal. The TME content of IBF seed depends on the form in which it is fed. When fed ground, the TMEn content was determined to be 1,974 kcal/kg. When fed whole, with supplemental grit, the TMEn content was 1,067 kcal/kg. Inclusion of IBF seed in broiler starter diets had adverse affects on both feed consumption and BW gain, even at a 5% inclusion level. Further studies are required to determine whether IBF seed could be included in diets for older broiler chicks or laying hens.