Associations between adolescent social media use and well-being are inconclusive, and studies using rigorous methodologies and objective measures are needed. Additionally, attention on what individual differences may moderate linkages between social media and well-being is necessary. We tested 1) how daily social media use (assessed via objective-reports and self-reports during an ecological momentary assessment period) relates to daily subjective well-being, 2) the prevalence and concordance between scholar-defined addiction-like social media use (ASMU) and participant perceptions of social media addiction, 3) how these constructs relate to subjective well-being, and 4) if these constructs moderate daily links between social media use and subjective well-being. In a sample of 103 adolescents (M[subscript age] = 16.48, 47% female), ASMU and perceived addiction were highly correlated but some adolescents' classification differed when cross-referencing. Both were similarly associated with demographics and depressive symptoms. Self-reported, but not objectively-recorded, social media use was related to greater ASMU and perceived addiction. Links between social media use and well-being were inconsistent, with no moderation by ASMU or perceived addiction. Most adolescents endorsed some degree of ASMU, and future research should examine how social media-triggered disruptions to daily functioning relates to well-being.