BackgroundThe literature emphasizes the importance of sexual orientation in the self-identification and decision-making processes related to diagnosis and gender affirmation among transgender individuals. A deeper understanding of these relations can be attained by synthesizing qualitative studies that explore the personal meanings transgender individuals attribute to their sexual orientation.AimsThe aim of this study was to systematically review the literature investigating the meaning of sexual orientation in the lives of transgender people.MethodsOriginal studies published on PubMed, Scopus, PsycInfo, and Web of Science between 2010 and 2020 were examined. Fourteen qualitative studies met the inclusion criteria and were included in the review. Each of them was analyzed using a thematic synthesis method to identify key themes.ResultsThe thematic synthesis revealed that sexual orientation interplays with gender identity at individual, relational, and social levels, while transgender people often report confusion between the two and the influence of one identity on the development of the other.DiscussionThe findings both inform future research directions and have clinical implications, such as increasing awareness of the interrelated influence of sexual orientation and gender identity. Clinicians should approach the labels adopted by patients as possibly subject to change, supporting clients in their self-exploration process.