Utilization of cover crops has increased rapidly in the United States. However, more information is needed on the proper cover crop termination timing to maximize weed control and crop yield. Field experiments were conducted in 2017 and 2018 at two locations in Indiana to evaluate the influence of cover crop species, termination timing, and herbicide treatment on winter and summer annual weed suppression and corn yield. Cereal rye and canola cover crops were terminated early or late (2 weeks before or after corn planting) with a glyphosate- or glufosinate-based herbicide program. Canola and cereal rye reduced total weed biomass collected at termination by up to 74% and 91%, in comparison to fallow, respectively. Canola reduced horseweed density by up to 56% at termination and 57% at POST application compared to fallow. Cereal rye reduced horseweed density by up to 59% at termination and 87% at POST application compared to fallow. Canola did not reduce giant ragweed density at termination in comparison to fallow. Cereal rye reduced giant ragweed density by up to 66% at termination and 62% at POST application. In general, termination timing had little to no effect on weed biomass and density reduction in comparison to the effect of cover crop species. Cereal rye reduced corn grain yield at both locations in comparison to fallow, especially for the late termination timing. Corn grain yield reduction up to 49% (4,770 kg ha-1) was recorded for cereal rye terminated late in comparison to fallow terminated late. Canola did not reduce corn grain yield in comparison to fallow within termination timing; however, late terminated canola reduced corn grain yield by up to 21% (2,980 kg ha-1) in comparison to early terminated fallow. Results from this study suggest that cereal rye planted at 90 kg ha-1 or canola planted at 6 kg ha-1 can be effective as cover crops for horseweed suppression prior to corn. Cereal rye can also effectively suppress giant ragweed emergence, while canola is not as effective at suppressing large-seeded broadleaves such as giant ragweed. Corn yield loss will likely occur with the use of cereal rye as a cover crop when no supplemental N fertilizers are applied preplant. These results also indicate that early-terminated cover crops can often result in higher corn grain yields than late-terminated cover crops in an integrated weed management program.