Purpose:　To　explore　the　impact　of　the　match　between　academic　pressure　and　peer　support　on　adolescents＇　sense　of　loneliness　and　examine　whether　social　connectedness　played　a　mediating　role,　using　a　polynomial　regression　and　response　surface　analysis.　Methods:　A　questionnaire　survey　was　conducted　with　1277　adolescents　from　two　cities　in　Sichuan　Province,　China,　to　investigate　their　academic　pressure,　peer　support,　social　connectedness,　and　sense　of　loneliness.Results:　(1)　Adolescents＇　sense　of　loneliness　positively　correlated　with　their　level　of　academic　pressure　and　negatively　correlated　with　their　degree　of　peer　support.　(2)　Social　connectedness　played　a　mediating　role　in　the　relationship　between　academic　pressure,　peer　support,　and　sense　of　loneliness.　(3)　Adolescents　with　high　academic　pressure　and　low　peer　support　had　weaker　social　connectedness　than　those　with　low　academic　pressure　and　high　peer　support.　(4)　Adolescents　with　high　academic　pressure　and　high　peer　support　had　stronger　social　connectedness　than　those　with　low　academic　pressure　and　low　peer　support.Discussion:　The　study　revealed　the　mechanism　through　which　a　match　(or　mismatch)　between　academic　pressure　and　peer　support　influenced　adolescents＇　sense　of　loneliness　and　validated　the　mediating　role　of　social　connectedness.　The　study　enriches　the　developmental　theory　of　adolescent　loneliness　and　provides　research　experience　for　future　interventions　targeting　adolescent　loneliness.