The study was conducted to determine whether state obesity-prevalence rates can be predicted by state differences in residents' levels on the Big Five personality variables (O. P. John & S. Srivastava, 1999). State obesity prevalence was the mean percentage of the state population from 2000 to 2005 with a body mass index > or = 30.0 as assessed by the Behavioral Risk Factor Surveillance System (Centers for Disease Control and Prevention, 2010), which currently interviews more than 350,000 adults annually. State neuroticism, extraversion, agreeableness, conscientiousness, and openness z scores, based on the responses of 619,397 residents to an Internet survey from 1999 to 2005, were taken from P. J. Rentfrow, S. D. Gosling, and J. Potter (2008). Alaska, Hawaii, and North Dakota had scores outside -3 and +3 standard deviations on at least 1 variable and were excluded as outliers. For the 47 remaining states, state obesity prevalence was significantly correlated with neuroticism (.35), agreeableness (.38), openness (-.44), socioeconomic status (-.74), white percentage (-.34), and urbanization (-.43). Multiple regression analysis showed that socioeconomic status could account for 54.0% of the criterion variance and that agreeableness, neuroticism, and openness together could account for another 17.1%.