Mental illness is a frequent comorbidity in chronic diseases including hypertension, yet integration of mental health screening into hypertension care remains limited, particularly in low- and middle-income countries. This systematic review synthesizes qualitative evidence on healthcare providers' experiences of integrating mental illness screening and management into hypertension care. Qualitative studies published between 2010 and 2025 were identified through searches of PubMed, Scopus, PsycINFO, Web of Science, and Africa Wide Information. Out of 114 studies, 7 studies met the inclusion criteria, and their quality was rated using the Critical Appraisal Skills Programme (CASP) qualitative checklist. An inductive thematic synthesis was conducted, followed by deductive mapping using the Consolidated Framework for Implementation Research. Key barriers included heavy workloads, stigma, limited training, and weak referral systems, while facilitators included training, collaboration, task-shifting, and community-based strategies. Findings highlight that integration is feasible but dependent on organizational capacity, workforce support, and how well it fits with local contexts. Overcoming these barriers and using the facilitators can improve the effectiveness and long-term success of integration efforts.