There is substantial clinical and public health evidence that video gaming, particularly online gaming, can become excessive and lead to psychological distress and functional impairment. This has led to the inclusion of gaming disorder as an official mental condition in the International Classification of Diseases, 11th Edition (ICD-11; World Health Organization, 2019). Psychological models recognize the importance of cognitive factors to explain the initiation, development, and maintenance of problematic gaming behaviors. This chapter will summarize some of the known cognitive factors associated with problem gaming and gaming disorder. These cognitions will be divided into two broad categories: (1) cognitive deficits (e.g., impaired executive functioning, hazardous decision-making, or deliberative processes) and (2) cognitive biases (e.g., attentional biases, cognitive distortions, dysfunctional cognitions). This chapter will review and synthesize available research findings and highlight their clinical implications for gaming disorder. The limitations of the research base are considered and some potential avenues for future research are proposed.