Being the first to ask the question whether (a) systematic interindividual differences in irony performance can be found and (b) whether this interindividual variance can be explained by personality and ability variables, the present thesis aims to paint a clearer picture of who is able or inclined to detect or use irony. The aim in dealing with these questions is to open up a new field of study for both personality and irony research by conceptualizing irony detection as an aptitude and irony use as an enduring tendency. The results support these expectations by demonstrably (a) linking the aptitude to detect irony to general mental ability and personality traits, and (b) linking the tendency to use irony to personality traits. More broadly, the results support the central claims in that they indicate (a) that there is systematic and measurable interindividual variance in irony detection and use, and (b) that a substantial amount of this interindividual variance can be explained by variables from the realm of ability and personality as two central domains of individual differences. Furthermore, the present thesis introduces a new means of assessing irony detection performance (i.e., including ironic praise as a previously neglected category of stimuli). As a secondary result, the present thesis also supports pre-existing assumptions about the role of humor in irony behaviors. The findings have implications for different fields of irony and humor research.