Background Although goiter is a major public health problem in Ethiopia and affects a large number of people, there was little evidence among adolescents particularly in Northern Ethiopia. This study was, therefore, aimed at investigating the prevalence of goiter and associated factors among adolescents in Gazgibla District, Northeast Ethiopia. Methods A community-based cross-sectional study was conducted among 596 adolescents from August 5–30, 2019. Data were collected using a structured questionnaire. Adolescents were assessed for goiter based on World Health Organization criteria. The level of iodine in household salt samples was tested using rapid test kit. Data were entered into EpiData version 3.1 and exported into Statistical Package for the Social Sciences version 22.0 for statistical analysis. Multivariable logistic regression analysis was done to control for all possible confounders and to identify predictors of goiter. Odds ratio along with 95% confidence interval (CI) was estimated to measure the strength of the association. Level of statistical significance was declared at P ≤ .05. Results The prevalence of goiter among adolescents was 42.5% (95% CI: 38.4%, 46.7%). Being a female (adjusted odds ratio [AOR] = 1.83, 95% CI: 1.18, 2.85), family history of goiter (AOR = 3.63, 95% CI: 2.31, 5.69), cabbage consumption at least once per week (AOR = 4.6, 95% CI: 2.42, 8.74), not consuming meat at all (AOR = 2.5, 95% CI: 1.17, 5.32), not consuming milk at all (AOR = 2.19, 95% CI: 1.19, 4.03), and inadequate iodine level of household salt (AOR = 7.05, 95% CI: 3.83, 12.97) were significantly associated with the development of goiter among adolescents. Conclusions The prevalence of goiter was very high in the study area. Therefore, the health sector of the district should invest efforts on improving the community’s awareness through disseminating key messages about iodized salt and iodine-rich foods.