Although there has been longstanding work on possibility thinking (PT), there is no current scale that researchers can use to measure and study this important action-based orientation. In this paper, we report on four studies with English and Polish speaking participants (N > 1,500) focused on developing and providing an initial evaluation of the Possibility Thinking Scale (PTS). Across the four studies, we examined the factor structure of the PTS by comparing one- and three-factor models and tested the links between PT and relevant correlates: divergent thinking, creative agency factors, and facets of Openness and Extraversion. After a series of replications presented in Studies 1 to 3, Study 4 (N = 491) explored revisions to the scale, using new items developed with input from Large Language Models. Taken together, our results indicate that the final version of PTS reflects three factors of one’s orientation to the possible (i.e. awareness, excitement, and exploration). Our results also indicate that the factors were associated with, but sufficiently distinct from related constructs. We close by discussing strengths and weaknesses of PTS and propose future directions for research.