Previous research has investigated the nature of imagination as a construct related to multiple forms of higher-order cognition. Despite the emergence of various conceptualizations of imagination, few attempts have been made to explore the structure of imagination as a trait in the context of existing hierarchically-nested personality dimensions. We present the Dual Facet Imagination Scale (DFIS) for measuring trait imagination that distinguishes between "experiential simulation" and "conceptual innovation," aligned with the two major subfactors (aspects) of the Big Five dimension Openness/Intellect. In two samples (N = 210 & 5771), we provide evidence of a consistent factor structure distinguishing experiential and conceptual descriptions of imagination, as well as validity as measures of facets of Openness and Intellect. The DFIS provides a trait measure of two major forms of imagination in line with mainstream models of the hierarchical structure of personality.