© 2021 L'Encéphale, ParisThis descriptive study was carried out to examine the relationship between smartphone addiction, peer relationships, and loneliness in adolescents. The sample consisted of 500 adolescents aged between 15–18 years, who were high school students in Central Anatolia region during the 2018–2019 academic year. The data of the study was collected through a questionnaire, Smartphone Addiction Scale-Short Version (SAS-SV), Friendship Qualities Scale (FQS) and UCLA Loneliness Scale (ULS). Statistical analyses included descriptive statistics, Shapiro-Wilk, and Spearman correlation test. The SAS-SV, FQS and ULS mean scores were 27.82 ± 11.53, 81.88 ± 15.68, and 41.99 ± 8.62, respectively. Results indicated there was a weak positive correlation between the companionship subscales of both FQS and ULS with SAS-SV. There was a weak negative correlation between the conflict subscales of FQS and SAS-SV. Providing a special education to adolescents and their parents to raise their awareness on the negative effects of smartphone addiction may be recommended.