The face is central to individual identity and gender presentation. Sex-based differences are seen at nearly every component and facet of the face, from the craniofacial structure to skin and soft tissue volume distribution. This chapter provides a framework for identification and analysis of sex-based differences in facial anatomy. Facial structure differences between ethnic groups will be examined. With advances in image analysis, this chapter will describe the role of three-dimensional (3D) facial morphometric facial sex differences in facial analysis. Collectively, these can then be used to guide individualized approaches to surgical planning to create greater congruence between patients’ existing physical features and goals for facial gender expression.