Rarely explored yet deeply consequential, this qualitative study explores how socioeconomic stigma is experienced, interpreted, and internalised as self-stigma among Malaysian adolescents from B40 families. Using a phenomenological research approach, semi-structured interviews were conducted with six late adolescents aged 18-25 years. The data were analysed thematically using Atlas.ti 9. The findings reveal that socioeconomic stigma is encountered through class-based labelling and social separation that mark economic difference in everyday interactions. These experiences do not lead directly to self-stigma but are first interpreted through processes of comparison, shame, and anticipation of social judgement. Over time, when such meanings are accepted as personally relevant, stigma becomes incorporated into self-evaluation, shaping self-regulation, relational withdrawal, and constrained aspirations. The study demonstrates that self-stigma develops through adolescents’ interpretive engagement with socially produced judgements during a critical period of identity formation and is shaped by socioeconomic position and cultural context. By foregrounding adolescents’ lived experiences, this study offers a process-oriented and contextually grounded understanding of stigma internalisation among socioeconomically marginalised adolescents.