BACKGROUND: The notion of unmet need for family planning indicates the gap between women's contraceptive practice and their reproductive intention. Although universal access to sexual and reproductive health services including contraceptive methods is a bedrock for sustainable development goals, the unmet need for contraception is high among young women in low-income countries including Ethiopia. The unmet need for contraception is associated with unintended pregnancy which most of the time end in unsafe abortion. Hence, this study aimed to assess the determinants of unmet need for family planning among young married women in Ethiopia using nationally representative data. METHOD: This study utilized secondary data collected in the 2016 Ethiopia Demographic and Health Survey (EDHS). A two-stage cluster sampling method was used. The analysis included a total of 2444 sexually active married young women (15-24 years). Multilevel logistic regression analysis was conducted to identify individual and community level factors associated with unmet need for contraceptives and the results were presented as adjusted odds ratio (AOR) at 95% confidence interval (CI), declaring statistical significance at a p-value <0.05 in all analyses. RESULTS: In this study, the prevalence of unmet need for contraceptive method among married young women was 18.4% [95% CI: (16.9, 20.0)]. Female head of the household [AOR: 1.62, CI (1.25, 2.11)], primary level of education [AOR: 1.53, CI: (1.16, 2.03)], family size ≥5 [AOR: 1.53, 95%CI: (1.22, 1.93)], undecided to have child [AOR: 2.86, 95%CI: (1.58, 5.20)] and infecund [AOR: 1.54, 95%CI: (1.08, 2.20)] were factors positively associated with unmet need for family planning. Whereas the odds of unmet need for contraceptive method was lower among women-initiated sex between 15-17 years and >17 years [AOR:0.72, 95%CI (0.53, 0.98)] and [AOR: 0.58, 95%CI: (0.40, 0.85)] respectively and community with high proportion of poverty [AOR: 0.68, 95%CI: (0.46, 0.99)]. CONCLUSION: The prevalence of unmet need for contraceptive methods among young married women was relatively high. Being female household head, age at first sexual intercourse, educational status of the woman, family size, desire for more children, and community poverty were significantly associated with unmet need for family planning. Hence, interventions targeting these special populations at the individual and community level would play a paramount role in meeting the unmet need for contraception among young married women in Ethiopia.