Abstarct: The use of cover crops as a non-chemical method for weed management has attracted increasing attention from researchers aiming to achieve sustainable agriculture. Finding the best cover crop that can effectively suppress weeds while minimizing competitive pressure on the main crop is a key factor in the effectiveness of cover crops for weed management. To evaluate the effects of cover crops on the growth, yield, and weeds control in three soybean cultivars, a factorial experiment was conducted in a randomized complete block design with three replications in two experimental fields in Golestan province, located in the cities of Gorgan and Aliabad Katoul, during the 2018-2019 growing season. The experimental factors were three soybean cultivars (Saman, Katoul, and Sari) as the first factor, and six weed management treatments, including pure soybean with conventional herbicide application, pure soybean with manual weeding, simultaneous planting of mungbean (Vigna radiata L.) as a cover crop with soybean, simultaneous planting of cowpea (Vigna unguiculata) as a cover crop with soybean, simultaneous planting of proso millet (Panicum miliaceum L.) as a cover crop with soybean, and pure soybean (weed-infested control) as the second factor. The results showed that weed interference significantly reduced chlorophyll a (20.27%), chlorophyll b (25.31%), total chlorophyll (14.23%), carotenoids (30.36%), nitrogen (31.48%), phosphorus (29.75%), and potassium (17.98%) in soybean leaves compared to the weeding treatment. Except for soybean stem height, which increased under the influence of cover crops and weeds, the leaf area index, number of pods per plant, number of seeds per pod, and 100-seed weight of soybean decreased significantly under weed presence. Soybean seed yield reduction due to weed interference ranged from 23.77% to 50%, depending on location and soybean cultivar. The use of mung bean, cowpea, and millet as cover crops reduced weed density by 95.48%, 94.67%, and 93.03%, respectively, and decreased weed dry weight by 98.07%, 97.62%, and 96.07%, compared to the no-weeding treatment. The results indicated that cover crops significantly reduced chlorophyll a and b, nitrogen and potassium content, number of seeds per pod, protein percentage, biological yield, and soybean seed yield compared to the weeding treatment. Among the cover crops, millet had a greater effect than cowpea and mungbean, leading to higher increases in nutrient content, leaf pigments, number of pods per plant, seeds per pod, and soybean yield compared to the no-weeding treatment. The results showed that the highest seed yield, 2047.1 kg/ha, was obtained from the interaction of the Saman cultivar under weed-free conditions in the Aliabad region, while the lowest seed yield, 935.35 kg/ha, was from the Sari and Katul cultivars under no weeding in the Gorgan region. The highest weed density, 15.9 plants/m², was observed under no weeding in Aliabad, and the lowest weed density was found in the millet cover crop treatment in both Gorgan and Aliabad regions. baxsed on the findings of this study, among the cover crops, millet, like mungbean and cowpea, effectively controlled weeds while exerting less competitive pressure on soybean. Therefore, millet is a better option as a cover crop for sustainable weed management, especially with taller soybean cultivars like Saman.