This research aims to develop a conceptual framework and propositions to establish and test the causal relationships between Industry 5.0 readiness (I5.0R), global value chain (GVC) participation, business competitiveness (BC), and sustainable business growth (SBG) of small and medium-sized enterprises (SMEs). This study focuses on Industry 5.0 readiness, evaluated through human-centricity, fairtrade practices, lean management, sustainability practices, and business competitiveness, measured by marketing, resources, production, and finance. Both constructs were developed and tested as higher-order constructs, while GVC participation and sustainable business growth were assessed as lower-order constructs. Data were collected from marine food processing SMEs in Thailand using a purposive sampling technique. This study tested and confirmed the content validity, construct validity, and reliability of both lower and higher-order models. Using partial least squares structural equation modeling (PLS-SEM) with bootstrapping (n = 1000), the results indicated significant positive impacts of Industry 5.0 readiness on GVC participation, Industry 5.0 readiness on business competitiveness, GVC participation on business competitiveness, and business competitiveness on the sustainable business growth of SMEs. Additionally, business competitiveness was found to mediate the relationship between Industry 5.0 readiness and sustainable business growth. These findings contribute to the literature on Industry 5.0, GVCs, and SME business competitiveness, offering practical insights for SMEs and policymakers aiming to enhance sustainable growth through strategic readiness and competitiveness in Industry 5.0 practices. The implications and directions for further research in Industry 5.0 readiness of SMEs are presented.