Using a socioecological approach, this review describes the peer-reviewed literature on oral pre-exposure prophylaxis (PrEP) among both cisgender (cis women) and transgender women (trans women) in the U.S. A search of the PubMed database and HIV-related conference abstracts generated over 2,200 articles and abstracts. Of these, 103 fulfilled review inclusion criteria. Most of the existing research presents findings on individual-level factors associated with PrEP use such as willingness and perceived barriers. There was far less investigation of factors related to PrEP at more distal ecological levels. Though trans women are at greater risk of HIV infection than cisgender women, less is known about this population group with respect to PrEP despite their inclusion in many major clinical trials. Further, the literature is characterized by a persistent conflation of sex and gender which makes it difficult to accurately assess the reviewed research on HIV prevention and PrEP apart from risk group. Informed by these findings, we highlight specific opportunities to improve access to PrEP and reduce socioecological barriers to PrEP care engagement for cisgender and transgender women.