Theorists have long observed that individuals can demonstrate both masculinity and femininity. However, measures of gender norm conformity are often developed with single-gender samples. This has lead to an absence of information regarding the psychometric properties of conformity to masculine norms among women. To facilitate the study of masculinity-related constructs across gender, the present study investigated measurement invariance of the factor structure of the Conformity to Masculine Norms Inventory-46 (CMNI-46) in a sample of 335 women and 330 men, age 18–83. Results demonstrated configural and metric invariance, suggesting that scores on the CMNI-46 are comparable across women and men. The groups differed on scalar invariance, as expected, suggesting differing overall levels of endorsement of masculine norms, with men scoring reliably higher than women. Overall, we believe researchers may feel confident in applying and interpreting the CMNI-46 with female samples, although some conceptual concerns remain.