Colonic diverticulitis is rare in pediatric populations. In cases of right-sided colonic diverticulitis, the symptoms can mimic those of acute appendicitis, leading to potential misdiagnosis of acute appendicitis. We report a case of ascending colonic diverticulitis in a 15-year-old young man who presented with abdominal pain migrating from the epigastrium to the right lower quadrant, initially raising suspicion for acute appendicitis. The patient presented to a local clinic with worsening pain and was referred to our department due to right lower quadrant tenderness and an elevated white blood cell count. Contrast-enhanced computed tomography revealed a solitary diverticulum in the ascending colon, accompanied by wall thickening and pericolic fat stranding, confirming the diagnosis of diverticulitis. The patient was successfully treated with intravenous antibiotics, and his symptoms resolved without surgical intervention. This case highlights the importance of considering right-sided diverticulitis in the differential diagnosis of right lower quadrant pain, particularly in regions where it is more prevalent. Additionally, diverticulitis should be included in the differential diagnosis when evaluating patients with pain that migrates from the epigastrium to the right lower quadrant. Imaging modalities, particularly computed tomography, may play a vital role in distinguishing this condition from acute appendicitis.