Openness to experience is the broadest personality domain of the Big Five, including a mix of traits relating to intellectual curiosity, intellectual interests, perceived intelligence, imagination, creativity, artistic and aesthetic interests, emotional and fantasy richness, and unconventionality. Likewise, creative achievement is a broad construct, comprising creativity across the arts and sciences. The aim of this study was to clarify the relationship between openness to experience and creative achievement. Toward this aim, I factor analyzed a battery of tests of cognitive ability, working memory, Intellect, Openness, affect, and intuition among a sample of English Sixth Form students (N = 146). Four factors were revealed: explicit cognitive ability, intellectual engagement, affective engagement, and aesthetic engagement. In line with dual-process theory, each of these four factors showed differential relations with personality, impulsivity, and creative achievement. Affective engagement and aesthetic engagement were associated with creative achievement in the arts, whereas explicit cognitive ability and intellectual engagement were associated with creative achievement in the sciences. The results suggest that the Intellectual and Openness aspects of the broader openness to experience personality domain are related to different modes of information processing and predict different forms of creative achievement.