Seat belt use can significantly reduce fatalities in motor vehicle crashes (Kahane, 2000). Nevertheless, the current U.S. seat belt use rate of 89.6% (Enriquez & Pickrell, 2019) indicates that a relatively small but pervasive portion of the population does not wear seat belts on a full-time basis. Whereas much is known about the demographic predictors of seat belt use, far less is understood about psychological factors that predict individual proclivities toward using or not using a seat belt. In this study, we examined some of these potential psychological predictors. A probability-based web survey was conducted with 6,038 U.S. residents aged 16 or older who reported having driven or ridden in a car in the past year. We measured self-reported seat belt use and 18 psychological constructs and found that delay of gratification, life satisfaction, risk aversion, risk perception, and resistance to peer influence were positively associated with belt use. Impulsivity and social resistance orientation were negatively associated with belt use. Prior research has shown that psychological factors like delay of gratification, risk aversion/perception, and impulsivity predict other health behaviors (e.g., cigarette smoking, sunscreen use); our results extend this literature to seat belts and can aid the development of traffic safety programs targeted at non-users who-due to such factors-may be resistant to more traditional countermeasures such as legislation and enforcement.Copyright © 2020. Published by Elsevier Ltd.