This study evaluated how feeding the common carp (Cyprinus carpio) at multiple protein levels affected their growth and body composition during the winter season. Four experimental diets with varying protein levels were tested, with  protein levels of 30% (T1), 28% (T2), 26% (T3), and 35% (T4), respectively. Fish were obtained and kept in a water culture pond with dimensions of 4x4x3 meters. Fish average weight was 148.7± 5.76g, while its length measurements were recorded at 24.33± 2.45cm, fork length at 21.15± 2.34cm, and standard length at 18.96± 1.66cm. The fish were purchased from a hatchery farm in Mosul City, northern Iraq. For 90 days, the fish were fed experimental feed once daily until they reached satiation. Compared to other treatments, fish fed T2 (28% protein) showed higher daily weight gain, total weight gain, weight growth rate, relative growth rate, metabolic growth rate, and specific growth rate. The feed diet T2 had the highest Fulton and modified condition factor, reaching 4.84± 0.14; 2.81± 0.03, whereas the highest condition factor was recorded (3.34± 0.16; 2.1± 0.03) for feed treatment T3. Feeding indicators in the feed treatment T2, such as total feed intake, daily feed consumption, and total protein productivity, were greater. The protein efficiency ratios of the fish groups fed formulations T2, T1, and T3 were recorded at 1.32± 0.004,  1.34b± 0.004, and 1.425c± 0.007%, respectively. In comparison, a significant difference was detected for the fish group consuming feed T4, with a value of 1.058d± 0.009%. For the length-weight relationships, an isometric growth (26, 35%) was recorded for T3, an allometric positive growth for T2, and a negative growth for T1.