Background: The negative impact of caregiving on carers’ physical and psychological wellbeing is well documented. Carers of mental health inpatients face additional burden, and report predominantly negative experiences of inpatient services. It remains unclear why, despite policies intended to improve inpatient experiences. A comprehensive review of carers’ inpatient experiences is needed to understand carer needs. As such, we aimed to conduct a systematic review and thematic synthesis of carer experiences of inpatient mental health care. Methods: We searched MEDLINE, PsycINFO, Embase and CINAHL for qualitative studies examining carer experiences of mental health inpatient care. Searches were supplemented by reference list screening and forward citation tracking of included studies. Results were synthesised using thematic synthesis. Our protocol was registered on PROSPERO (CRD42020197904) and our review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Findings: 12 studies were included from 6 countries. Four themes were identified: the emotional journey of inpatient care, invisible experts, carer concerns about quality of care for their loved one and relationships and partnershipInterpretation: Greater attention must be paid to ensure carers are well-supported, well-informed, and included in care. More emphasis must be placed on fostering positive relationships between carers, service users and staff and in facilitating continuity of care across inpatient and community services to provide carers with a sense of security and predictability. Further research is needed to explore differences in experiences based on carer and service user characteristics and global context, alongside co-production with carers to develop and evaluate future guidelines and policies.