Human intelligence is one of the main broad domains of interest in individual differences research. Moreover, it is a common believing that playing chess well implies a high level of intelligence. Whether chess players are more intelligent on average than the general population is another recurrent question that has elicited a considerable body of research. The scientific evidence about these topics, however, remains largely inconclusive. The chapter describes first the main models and approaches about the scientific study of human intelligence. The studies about the relation of intelligence with chess playing are organized by splitting the available evidence obtained from children and adults. The final section in the chapter includes novel empirical findings comparing chess skill and chess motivation in the prediction of chess performance, suggesting that non-cognitive traits might be also influential for chess performance.