Non-suicidal self-injury (NSSI) is an important mental health concern among emerging adults and has been linked to adverse childhood experiences, including emotional neglect. However, the interpersonal and emotional processes associated with this relationship remain insufficiently understood, particularly in non-Western contexts. This study examined the direct and indirect associations among childhood emotional neglect, loneliness, emotion dysregulation, and NSSI in emerging adults. A cross-sectional quantitative design was employed with 386 participants aged 18–29 years recruited through online survey distribution. Participants completed standardized measures of childhood emotional neglect, loneliness, emotion dysregulation, and NSSI. Structural Equation Modeling (SEM) with 5,000 bootstrap resamples was used to test the hypothesized direct and indirect associations. Childhood emotional neglect was positively associated with loneliness, emotion dysregulation, and NSSI. Loneliness was positively associated with emotion dysregulation and NSSI, while emotion dysregulation was positively associated with NSSI. Significant specific indirect associations were observed through loneliness and emotion dysregulation, and the serial indirect association through loneliness followed by emotion dysregulation was also significant. These findings support the statistical plausibility of an attachment-informed interpersonal–emotion regulation framework linking childhood emotional neglect with NSSI. Given the cross-sectional design, the indirect associations should not be interpreted as evidence of temporal or causal mechanisms. The findings highlight loneliness and emotion dysregulation as relevant interpersonal and emotional correlates that may inform psychological assessment and future intervention development for emerging adults reporting emotional neglect and NSSI.