The current research aims to investigate the serial-multiple mediation of general belongingness and life satisfaction in the relationship between loneliness and attachment to parents and peers in adolescents. The participants of the research consisted of 218 high school students (F = 126, 57.8%; M = 92, 42.2%). Age of the participants' ranged between 14 and 18 with a mean of 15.84 (SD = 1.42). Instruments in the current research included the Personal Information Form, Inventory of Parent and Peer Attachment, UCLA Loneliness Scale, General Belongingness Scale, and Satisfaction with Life Scale. Data analysis was conducted using descriptive statistics, the Pearson correlation coefficient, ordinary least-squares regression analysis, and bootstrap method. Based on the research findings, the serial-multiple mediation of general belongingness and life satisfaction in the relationship between loneliness and attachment to parents and peers was found to be statistically significant. Findings of the study were discussed under the light of relevant literature, and some suggestions were made for future studies.