Sexual and romantic satisfaction are important aspects of sexual health and wellbeing, but they have not been thoroughly investigated among transgender and gender diverse (‘trans’) people in Australia. To address this gap and improve sexual health and wellbeing, we assessed the sexual behavior and relationships of a national sample of trans people in Australia, and factors associated with sexual and romantic satisfaction. We conducted a national survey of trans people from Australia in October-November 2018. The sample included 1,613 trans participants, of whom 353 (21.9%) were men, 397 (24.6%) were women and 863 (53.5%) were non-binary. Over 70% of the sample had been sexually active in the previous year, and 56.9% were in a relationship, but only 32.4% were satisfied with the sexual aspects and 47.1% with the romantic aspects of their lives. Sexual satisfaction was associated with younger age, being asexual, having more trans friends, more frequent sex, and using illicit drugs in the context of sexual activity. Anxiety or fear about sex was associated with less sexual satisfaction, as was being in an open relationship. Romantic satisfaction was associated with younger age, having non-binary partners, and being in a current relationship (particularly a monogamous one). Recent distress, anxiety, or fear about sex were associated with less romantic satisfaction. Participants reported a broad range of sexual relationships, but low levels of satisfaction with the sexual and romantic aspects of their lives. The findings underscore the importance of supportive partners, access to social support and peer networks of trans people, as well as access to mental health support and sex-positive, trans affirming counseling in sexual health services.