Suicidal thoughts and behaviors are a significant health concern for adolescents. Extant research suggests that sexual and gender minority adolescents are a vulnerable population at elevated risk for suicidal thoughts and behaviors, yet to date few studies have examined the unique associations between adolescent gender nonconformity and suicide risk. This study examined data from the Youth Risk Behavior Surveillance Survey (n = 7730) to estimate the association between gender nonconformity and high school-aged adolescents’ likelihood of endorsing four distinct suicide outcomes: suicidal ideation, suicide plans, any suicide attempts, and single vs. multiple suicide attempts. Multivariate logistic regression analyses were utilized to control for other known risk factors for suicidal thoughts and behaviors, including age, sex, sexual minority status, depression symptoms, and suicidal ideation. Results revealed that gender nonconformity was significantly associated with higher odds of reporting suicidal ideation, suicide plans, and multiple suicide attempts in the past year above and beyond other known risk factors. Gender nonconformity is an understudied vulnerability factor that should be taken into consideration by researchers and clinicians seeking to understand adolescents’ risk for suicidal thoughts and behaviors.