Habitual self‐control is defined as a trait‐like personal resource factor that facilitates the enactment of difficult intentions. A 14‐item Habitual Self‐Control Questionnaire (HSCQ) was developed to assess this trait. Reliability, factorial validity, and criterion validity were assessed in five undergraduate student subsamples with an overall N of 2224. Internal consistency was .81 across the entire sample, and test–retest reliability was .83 over a one‐month interval. The HSCQ showed a theoretically meaningful pattern in terms of convergent and discriminant validity and criterion validity in predicting a variety of health behaviours that relate to self‐control, including exercise, dieting behaviour, binge eating and weight loss success. Further, the HSCQ contributed uniquely to the prediction of health behaviours beyond alternative self‐control scales. In a longitudinal part of the study, the HSCQ added to the prediction of action plan completion and satisfaction beyond motivation and moderated the relationship between motivation and enactment of action plans as theoretically expected. In sum, the results provided strong evidence for the reliability and validity of the HSCQ and highlighted some theoretically meaningful differences to already existing measures of self‐control. Theoretical implications are discussed. Copyright © 2012 John Wiley & Sons, Ltd.