Tamburic-Ilincic, L., Brinkman, J. M. P., Sparry, E. and Hooker, D. C. 2015. Optimizing inputs for winter durum wheat in Ontario. Can. J. Plant Sci. 95: 361-368. Best management practices need to be determined for a new wheat class in Ontario: winter durum. The objectives of this study were to determine optimal nitrogen rates (75, 100, and 125 kg N ha^-1), seeding rates (400, 440, and 480 seeds m^-2), and fungicide applications on the grain yield, grain protein, and leaf disease control of ‘OAC Amber’ winter wheat durum at five field locations in Ontario. Seeding rates between 400 and 480 seeds m^-2 did not impact performance. Overall, fungicide applications at flag leaf and flowering increased grain yield by an average of 0.52 Mg ha^-1, increased seed weight and test weight, reduced powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici emend. É.J. Marchal] and septoria leaf blotch [Mycosphaerella graminicola (Fuckel) J. Schröt.] in the canopy, but decreased grain protein from 128 to 126 g kg^-1. Grain yields did not increase with N rates higher than 100 kg N ha^-1, and the response to N rate did not depend on the application of fungicides. Grain protein concentrations increased with N rates up to 125 kg N ha^-1, which was the highest N rate investigated in this study. An economic analysis is needed to determine the impact of agronomic management strategies specific to winter durum wheat in Ontario.