Disordered eating research has long considered the negative consequences of internalizing sociocultural appearance ideals (e.g., thin ideal, muscular ideal). However, the implications of internalizing a curvy or "hourglass" body shape remains unclear. The Hourglass Body Shape Ideal Scale (HBSIS) is a new self-report questionnaire that was developed and evaluated to appropriately measure the extent women subscribe to an hourglass body shape ideal. The measure was administered to a community and undergraduate sample of women via two separate online studies. Study 1 (N = 916) provided support for the factor structure as well as the convergent and discriminant validity of the HBSIS. The HBSIS was correlated with measures of appearance orientation, overweight preoccupation, and disordered eating. HBSIS was associated with disordered eating even after controlling for age, BMI, thin ideal and muscular ideal internalization. Further, higher HBSIS scores were associated with increased likelihood of having clinical levels of disordered eating symptoms. There were no racial and ethnic group differences on HBSIS. Study 2 (N = 195) replicated the factor structure of Study 1, in addition to its convergent and discriminant validity. The HBSIS allows for more precise examination of appearance-ideal internalization, capturing a unique construct understudied within eating pathology literature.