Perfectionism is a multidimensional personality characteristic associated with mental health problems. However, its features are commonly misunderstood, and many people are unaware of the risks it can pose. This study aimed to develop the first self-report measure of perfectionism literacy. That is, the degree of knowledge someone has about perfectionism, its features and consequences, and when and where to seek help if needed. The Perfectionism Literacy Questionnaire (PLQ) was validated over four stages using four samples of community adults (N = 1078 total; M[subscript age] = 37.17 years). In stage one, we generated a pool of items. In stage two, we used exploratory and confirmatory factor analysis to derive a 29-item, seven-factor measure. In stage three, we assessed relationships between the PLQ, perfectionism, and attitudes toward help-seeking for mental health support and found the PLQ is distinguishable from these constructs. In stage four, we examined whether the PLQ was responsive to change following an educational video on perfectionism. We found tentative evidence that minimal intervention can increase perfectionism literacy. Our findings suggest that the PLQ is valid and reliable and may be useful for educational purposes and primary prevention of mental health problems.