Children with unilateral cerebral palsy (CP) exhibit abnormal movements due to atypical pelvic movements and weakness of trunk muscles. We investigated the effects of abdominal muscle strengthening and pelvic control exercises on trunk control, abdominal muscle thickness change rate, and pelvic movement in children with unilateral CP. Fourteen children with unilateral CP were randomly divided into two groups, and abdominal muscle strengthening and pelvic control exercises were applied to the experimental group, and general physical therapy was applied to the control group, 30 min per session, twice a week, for a total of 8 weeks, respectively. The trunk control measurement scale (TCMS) was used to measure trunk control, ultrasonography was used to measure abdominal muscle thickness change rate, and a wearable gait analysis system was used to measure pelvic movement. As a result, in the experimental group, TCMS showed a significant increase within the group, and the rotation range of the pelvis significantly decreased within the group on the affected and nonaffected sides. There was a significant difference between the groups in the abdominal muscle thickness change rate of the internal oblique on the affected side. Improving trunk control through abdominal strengthening and pelvic control exercises affected the deep muscles on the affected side and contributed to a reduction in excessive pelvic rotation range. Therefore, abdominal muscle strengthening and pelvic control exercises may be suggested as intervention methods to improve function in unilateral CP.