Technical Abstract: Thickspike wheatgrass is widely used for rangeland seeding and revegetation projects in western areas of North America. However, thickspike wheatgrass does not produce high seed yields, and seed is often of poor quality, which often results in high seed prices and poor establishment following seeding. The identification of populations with higher seed yield and seed quality would ameliorate some of the problems associated with thickspike wheatgrass seeding by providing lower cost seed and a higher confidence of successful seedling establishment. The study described herein characterized the performance of 44 populations of thickspike wheatgrass found in the USDA-NPGS collection and the cultivars Bannock and Sodar for seed yield and quality over two production at a site near Eureka, UT, USA. The populations exhibited large variation for each trait evaluated. Eight populations consistently performed well for each trait and would be potential candidate populations for increased seed yield and quality for future germplasm releases of thickspike wheatgrass.