This study investigates mobile phone addiction (MPA) within Ghanaian families, addressing a gap in the literature that has largely examined usage patterns without considering the relational dynamics that shape and are shaped by technology use. Guided by Family Systems Theory, the study situates MPA within the context of family cohesion, adaptability, communication and conflict. Adopting an explanatory sequential mixed-methods design, the study integrated quantitative data from 2,660 participants with qualitative interviews of 40 purposively selected individuals. Key Family Systems Theory concepts, including differentiation of self, emotional triangulation, subsystem boundaries and intergenerational transmission, guided the interpretation of findings. Data were collected using an adapted Smartphone Addiction Scale and subscales from Family Adaptability and Cohesion Evaluation Scale IV and analysed through descriptive statistics, correlation, hierarchical regression and thematic analysis. Findings revealed higher MPA among adolescents and urban residents, strong negative associations with cohesion and communication, and positive associations with conflict, while adaptability remained stable. These patterns were interpreted through systemic and relational processes within Ghanaian family structures. The study concludes that MPA functions as a systemic disruption to family relational regulation and recommends contextually grounded interventions targeting communication, shared routines and intergenerational relational repair.