This study reports on the development and psychometric evaluation of the Interpersonal Sexual Objectification Scale (ISOS). Data from 576 college women were collected in three studies. Exploratory factor analysis uncovered two factors: Body Evaluation and Unwanted Explicit Sexual Advances; confirmatory factor analysis supported this factor structure. ISOS scores were internally consistent and stable over a 3-week period. Supporting its construct validity, ISOS scores were (a) strongly related to sexist degradation; (b) slightly to moderately related to other sexist events, self-objectification (i.e., body surveillance and internalization of the thin-ideal), and body shame; and (c) unrelated to socially desirable responding. The relationship between ISOS scores and body shame was fully mediated by self-objectification, providing additional evidence for its construct validity. Furthermore, the ISOS garnered incremental validity, as it predicted self-objectification above and beyond the variance accounted for by sexist events.