The aim of this study is to investigate the effects of peer relationships in adolescents to happiness. In line with this general purpose, hypothetical model which examining the effects of peer relations to happiness was tested. Research was conducted on 162 adolescents, 84 of whom (51.9%) were female and 78 (48.1%) of whom were male. Peer Relationship Scale (PRS) and Oxford Happiness Questionnaire Short Form (OHQ-S) were used as data collection tools. The model was tested by Structural Equation Modeling. In the result of analysis, it was seen that peer relations predict happiness in direct, positive and significant level. This result indicates that peer relations is a factor to increase happiness in adolescents.