Cardiac computed tomography (CCT) has increasingly been used in the assessment of both children and adults with congenital heart disease (CHD), in part due to advances in CCT technology and an increased prevalence of adults with palliated CHD. It serves as a complimentary modality to echocardiography, cardiac magnetic resonance imaging and cardiac catheterization. CCT can provide unique diagnostic information, is less invasive and less likely to require sedation compared to other modalities. Detailed knowledge of individual patient cardiac anatomy, physiology, surgical repair and possible residual lesions are paramount to optimal CCT imaging. This comprehensive review details the use of CCT both pre- and postoperatively for the most common CHD diagnoses. We also aim to highlight some new and innovative technologies that have become available and can further optimize CCT imaging for CHD patients.