Background & Rationale: Research on frailty often refers to physical dimension, including increased risks of falls, disability, hospitalisation and mortality. However, evidence shows the importance of social dimension of frailty - reduced support, limited participation and weakened social networks. Older migrants are particularly vulnerable due to disrupted ties, migration status, language barriers and cultural dislocation. Yet little is known about how social frailty is understood within culturally diverse groups, including Southeast Asian (SEA) migrants. This study explores their perceptions to inform a culturally sensitive social frailty scale. Methods: Data were collected from 16 in-depth interviews and 1 focus group with older SEA adults (65+), carers and health, social care professionals (40+). Thematic coding using NVivo 16 examined how migration experiences, cultural expectations, barriers, intergenerational ties and digital connections shape social frailty. Results: Most participants had not heard the term “social frailty.” Beyond well-known factors, e.g., limited social engagement, weak support networks, financial strain, low wellbeing and limited literacy, they identified SEA-specific dimensions missing from existing scales. These included language barriers, migration/visa status, cultural exclusion, racism and discrimination, difficulty accessing services, religious needs, job-seeking challenges and transnational family ties. Participants suggested additional domains, e.g., cultural participation, equality and acceptance, and migrant-accessible support. Discussion & Conclusion: Social frailty among SEA migrants is shaped by relational, cultural and migration-related factors not captured in current frameworks. Developing a culturally appropriate scale will require incorporating these domains and further research with diverse SEA groups. A deeper understanding of migrant social frailty can guide more equitable care models and targeted interventions.