This research discusses the negotiation of transgender identity depicted  in Torrey Peter’s Novel Detransition, Baby. The aim of this research is to find out the identity of transgender by negotiation in this novel. The researcher applied Judith Butler theory Gender performativity in providing the data. This research used note taking as the instrument. The findings show highlight Reese’s conviction in identifying herself  as a woman, a transwoman, showcasing the fluid and complex nature of gender identity and Ames’s detransition journey involves transitioning between genders and displaying various masculine and feminine traits, emphasizing the fluidity of gender and challenging established social norms. This finding also reveal a deeper understanding of the complex experiences of transgender identities and individual transgender journeys aligns with Judith Butler’s concepts of gender performativity.