ObjectivesIt is important that allied health professionals (AHPs) are prepared for clinical practice from the very start of their working lives to provide quality care for patients, for their personal well-being and for retention of the workforce. The aim of this study was to understand how well newly qualified AHPs were prepared for practice in the UK.DesignSystematic review.Data sourcesEmbase, MEDLINE, CINAHL, ERIC and BEI were searched from 2012 to 2024. Grey literature searching and citation chasing were also conducted.Eligibility criteriaWe included primary studies reporting the preparedness for practice of UK graduates across 15 professions; all study types; participants included graduates who were up to 2 years postgraduation, their supervisors, trainers, practice educators and employers; and all outcome measures.Data extraction and synthesisA standardised data extraction form was used. Studies were quality assessed using the Quality Appraisal for Diverse Studies tool. 10% of articles were independently double-screened, extracted and quality assessed; 90% was completed by one researcher.Results14 reports were included (9 qualitative, 3 mixed-method and 2 quantitative). Six papers focused on radiographers, three on a mixture of professions, two on paramedics, and one each on physiotherapists, clinical psychologists and orthotists. An important finding of the review is the paucity and low-medium quality of research on the topic. The narrative synthesis tentatively suggests that graduates are adequately prepared for practice with different professions having different strengths and weaknesses. Common areas of underpreparedness across the professions were responsibility and decision-making, leadership and research. Graduates were generally well prepared in terms of their knowledge base.ConclusionHigh-quality in-depth research is urgently needed across AHPs to elucidate the specific roles, their nuances and the areas of underpreparedness. Further work is also needed to understand the transition into early clinical practice, ongoing learning opportunities through work, and the supervision and support structures in place.PROSPERO registration numberCRD42022382065.