Common mental disorders (CMDs) among adolescents may hamper their psycho-social development. This study evaluated the prevalence and determinants of CMD like depression and anxiety among late adolescents of an age of 15--19 years residing in an urban resettlement colony of southeast Delhi. A community-based cross-sectional study was carried out among 556 randomly selected adolescents. CMD was assessed using Mini International Neuropsychiatry Interview - Kid version 6 (MINI-Kid) based on DSM-IV TR and compliant with ICD-10 definitions of CMD. The associated risk factors were studied using a self-developed semi-structured interview schedule and analyzed using multi-variable logistic regression. A total of 491 adolescents were interviewed (a response rate of 88.3%), of whom 247 (50.3%) were female and 210 (42.8%) belonged to a lower-middle socio-economic status. The lifetime prevalence of CMD was 34% [95% confidence interval (CI): 29.8-38.2]. Of the total, 22.4% (95% CI: 18.7-6.1) of the participants reported depression and 6.7% (95% CI: 4.5-8.9) reported generalized anxiety disorder during their lifetime. Female sex [adjusted odds ratio (aOR) 2.1, 95% CI: 1.4-2.2], experiencing a stressful event in the past 6 months (aOR 4.7, 95% CI: 3.1-7.3), and smoking tobacco (aOR 2.0, 95% CI: 1.2-7.4) significantly increased the odds of having CMD in multi-variate analysis. There is a high prevalence of CMD among adolescents residing in urban resettlement colonies of Delhi, which is composed mostly of people belonging to lower socio-economic strata. Hence, tailored intervention at stress management with promotion of healthy lifestyle is needed for this age group.