Background: A vast amount of research has demonstrated the numerous adverse health risks of short sleep duration and poor sleep health among the general population, and increasing studies have been conducted among lesbian, gay, and bisexual individuals. However, although poor sleep health is disproportionately experienced by sexual and gender minority populations, little research has examined sleep quality and associated factors among transgender and gender nonbinary (TGNB) individuals. This study qualitatively explored the relationship that factors such as gender identity, mental health, and substance use have with sleep health among a sample of TGNB individuals in New York City. Methods: Forty in-depth interviews were conducted among an ethnically diverse sample who identified as transgender male, transgender female, and gender nonbinary from July to August 2017. All interviews were transcribed, coded, and thematically analyzed for domains affecting overall sleep, including mental health, gender identity, and various coping mechanisms to improve overall sleep. Results: TGNB interview participants frequently described one or more problems with sleeping. Some (15%) participants suggested that mental health issues caused them to have difficulty falling asleep, but that psychiatric medication was effective in reducing mental health issues and allowing them to sleep. An even larger number (35%) told us that their gender identity negatively impacted their sleep. Specifically, participants described that the presence of breasts, breast binding, stress and anxiety about their identity, and concerns about hormonal therapy and gender-affirming surgery were all reported as contributing to sleep problems. Given these sleep challenges, it is not surprising that most (60%) participants used various strategies to cope with and manage their sleep problems, including prescription and over-the-counter sleep medications (33%) and marijuana (18%). Conclusions: Our findings document that sleep health is frequently an issue for TGNB individuals, and they also offer insight into the various ways that TGNB individuals attempt to cope with these sleep problems. Sleep health promotion interventions should be developed for TGNB people, which would promote positive mental health, reduce the risk of pharmaceutical adverse events, and help alleviate psychosocial stress in this target population.