ObjectiveThis was a cross‐sectional and descriptive study to determine the social media and Internet addiction levels of adolescents.Design and MethodsThe data were collected between September and December 2023. A sociodemographic data collection form, The Social Media Addiction Scale for Adolescents, and The Internet Addiction Scale for Adolescents were used to collect data. An independent sample t‐test was used to compare the mean differences between the two groups. A one‐way ANOVA test was used to compare mean differences between multiple groups, and Pearson's correlation analysis was used to examine the relationships between quantitative variables and scale scores.ResultsNo significant relationship was found between adolescents' gender and age and addiction levels (p > 0.05). On the other hand, addiction levels differed significantly by school type and district (p < 0.05). Students in selective schools and secondary schools had lower addiction levels, and those in open‐admission high schools had higher addiction levels (p < 0.05). The highest level of addiction was found in Çankaya district and the lowest in Altındağ district. Daily online time and social media time increased addiction (p < 0.05). Safe Internet use and receiving support from nurses affected addiction levels (p < 0.05).ConclusionThe results show that adolescents aged 12−18 years are at significant risk of social media and Internet addiction. Therefore, it is recommended that nurses support these young people, assess their risks, and identify specific tasks.