Background: Currently the prevalence of obesity and overweight increase worldwide and adolescent are one of the vulnerable group to be affected. Reduced physical activity and sedentary behavior including screen time have given attention as a potential risk for high prevalence of overweight/obesity. But in spite of this fact there is little information on the association between screen time and increase overweight/obesity in our setting Objective: The study aimed at determining prevalence of time spent on screen above the recommendation and its relationship with overweight/obesity among secondary school adolescents in Addis Ababa, Ethiopia, in 2018. Method: School based cross sectional study was conducted among adolescent in Addis Ababa, Ethiopia. Sample size was calculated using single population proportion formula and final sample size become 550. Data were collected by using interviewer administered questionnaires. Finally, Descriptive statistics, bivariate analysis and multivariable logistic regression analyses was performed by using SPSS software version 20 and P-value less than 0.05 was used to declare statistically significant association. Result The study found that the mean screen time in the study population was 4.1±2.2 hr. per a day. In which 290 (53.7%) of adolescents spent more than 2hr. on screen. And the prevalence of overweight and obesity were 12.3% and 1.85% respectively. Female sex AOR 1.90 (1.05-3.43), high socio-economic status AOR 2.86 (1.06-7.73), high screen time AOR 3.01 (1.53-5.90), eating habit while watching TV AOR 4.05 (1.83-9.03), physical activity AOR 0.27 (0.13-0.59) were found to have significant association with overweight/obesity. Conclusion and recommendation This study demonstrated a 53.7% prevalence of screen time above recommended amount and also a positive association between longer periods of screen time and overweight/obesity among adolescents in Addis Ababa. Therefore Parents and adolescents should be aware about this association and should be encourage to participate their children in other means of recreational activity.