Parental involvement in curriculum governance has attracted growing scholarly attention, yet in Sub-Saharan Africa most empirical research on Competency-Based Curriculum (CBC) implementation has concentrated on instructional and material support roles, leaving decision-making participation as a governance mechanism undertheorised. This convergent parallel mixed-methods study examined the association between parental decision-making involvement and CBC governance effectiveness in public junior secondary schools in Sotik Sub-County, Bomet County, Kenya, with the secondary aim of proposing a Community Governance Model for CBC Implementation (CGM-CBC). The target population comprised headteachers, teachers, parents of enrolled learners, and Grade 8 students across five school zones. Stratified random sampling yielded a target sample of 398; 378 respondents (19 headteachers, 114 teachers, 124 parents, 121 students) returned complete instruments, yielding a response rate of 94.97%. The quantitative strand employed a single-predictor standard regression; qualitative data from semi-structured interviews (n = 10) and focus group discussions (five FGDs; total participants 30–40) were subjected to Braun and Clarke’s (2006) six-phase thematic analysis. Results revealed a strong positive association, r(376) = .86, p < .001; R² = .75, indicating that parental decision-making involvement was associated with 75% of the variance in CBC governance effectiveness. The magnitude of this association is discussed critically in relation to common method variance and contextual factors. Five qualitative themes corroborated and explained the mechanisms: parents as governance actors; shared decision-making and accountability; community ownership of CBC; barriers to governance participation; and leadership as governance enabler. The study proposes the CGM-CBC as a five-stage model—parental representation, shared decision-making, collaborative governance, community ownership, and sustainable implementation—derived inductively from empirical themes and deductively from Epstein’s (2002) involvement typology, Participatory Governance Theory (Fung, 2006), and Arnstein’s (1969) ladder of participation. Findings are interpreted as associational, contextually specific, and subject to the constraints of a cross-sectional self-report design.