Nearly 33 million female youths have an unmet need for voluntary family planning (FP), meaning they are sexually active and do not want to become pregnant. In Ethiopia, age at marriage remains low: 40% and 14% of young women aged 20–24 were married by the ages of 18 and 15, respectively. Despite increases in FP use by married 15- to 24-year-olds from 5% in 2000 to 37% in 2016, unmet need remains high at 19%. Supply-and-demand factors have been shown to limit FP use, yet little is known about how stigma influences FP use among youth. This study validates an anticipated stigma (expectation of discrimination from others) index and explores its effect on unmet need. A cross-sectional survey was implemented with 15- to 24-year-old female youth in Ethiopia in 2016. The analytic sample included married respondents with a demand (met and unmet need) for FP (n=371). A five-item anticipated stigma index (Cronbach’s α=0.66) was developed using principal component factor analysis. These items related to fear, worry and embarrassment when accessing FP. The findings showed that 30% agreed with at least one anticipated stigma question; 44% had an unmet need; 58% were married before age 18; and 100% could name an FP method and knew where to obtain FP. In multivariate regression models, youth who experienced anticipated stigma were significantly more likely to have an unmet need, and those who lived close to a youth-friendly service (YFS) site were significantly less likely to have an unmet need. Interventions should address anticipated stigma while focusing on social norms that restrict married youth from accessing FP; unmet need may be mitigated in the presence of a YFS; and the anticipated stigma index appears valid and reliable but should be tested in other countries and among different adolescent groups.