Dietary pattern analysis allows us to characterize the dietary intakes of individuals rather than nutrient intake data and strongly predicts disease risks. The relationship between food intake and adolescents' nutritional health is not well understood yet. Therefore, this study aimed to generate evidence for context-specific dietary intervention for adolescents. This study aimed to determine dietary patterns and their relationship with nutritional outcomes and identify the contributing factors among adolescents in the Agrarian Community of Northwest Ethiopia. A cross-sectional survey was conducted among 622 randomly selected adolescents. Dietary data were collected over a 1-week recall period using the Food Frequency Questionnaire (FFQ). After testing the basic assumptions, an exploratory factor analysis was conducted to determine the dietary patterns. Anthropometric data on weight and height were collected to determine the nutritional status using WHO Anthroplus 2010 software. A chi-square test was conducted to evaluate the effect of different dietary patterns on nutritional outcomes. A multivariable binary logistic regression model was used to identify factors affecting the dietary patterns of adolescents. Three types of dietary patterns, namely, traditional, mixed, and animal-source foods with traditional alcoholic beverage consumption were identified. These dietary patterns explain 58.64% of the variance in adolescent diet in the study setting. The burden of stunting was 15.12% vs. 11.21, 19.40% vs. 6.94, and 8.36% vs.17.97% among adolescents with lower traditional, mixed, and higher animal sources with alcoholic dietary pattern consumption habits, respectively (value of p <0.05). Adolescents who resided in low-land agroecology (AOR = 2.44; 95% CL: 1.24, 4.81) and had access to animal-source foods (AOR = 1.64; 95% CI: 1.04, 2.60) were associated with lower consumption of traditional dietary patterns. Similarly, adolescents who resided in low-land (AOR = 1.80; 95% CI: 1.18, 2.74) had formal education (AOR = 2.38; 95% CI: 1.35, 4.19) and had poor nutrition knowledge (AOR = 2.83; 95% CL: 1.55, 5.19) were associated with lower consumption of mixed dietary patterns. Moreover, adolescents residing in the high-land (AOR = 2.50; 95% CI: 1.37, 4.56) and being female (AOR =1.87; 95% CI: 1.27, 2.74) were significant factors associated with lower consumption of animal-sourced foods with traditional alcoholic beverage consumption patterns. Multidimensional modifiable factors were explored that could be targeted for public health interventions for the identified dietary patterns. Integrated and multifaceted dietary intervention approaches are needed to promote healthy diets and discourage the consumption of unhealthy diets to reduce undernutrition in the study area and similar settings.