Compared to cisgender individuals, transgender and gender nonconforming (TGNC) individuals report health disparities across various domains. These include general health, physical health, mental health, health behaviors, and health care access and utilization. Romantic partnership status is underexplored as a potential protective factor of health among TGNC individuals. In heterosexual and sexual minority individuals, being partnered generally relates to better health than being unpartnered. Using U.S. Behavioral Risk Factor Surveillance System (BRFSS) data, we conducted the first tests of partnership-health associations among TGNC individuals (N = 783), using health outcomes from the five health domains listed above. We ran binomial logistic regressions across 3 gender identity groups—trans men, trans women, and GNC individuals—testing partnership status as a predictor of each health outcome. We expected to find support for positive partnership-health associations across groups. Findings were mixed, overall. Partnership related to better health most frequently among trans women, predicting better general health, less depression, less smoking and heavy drinking, and having health coverage. Among GNC individuals, partnership predicted only increased likelihood of recent dentist visit. Among trans men, partnership predicted only decreased likelihood of recent medical check-up. Findings provide the first evidence for multidomain partnership-health associations, and differences in these associations by gender identity, among TGNC individuals. Partnership may be a protective health factor among trans women particularly and may relate to health disparity reduction between trans women and general population members. Findings encourage continued large-scale data collection on gender identity, partnership, and health.