Background: Psychosis is a mental disorder that, despite its low prevalence, causes high disease and economic burden. Inadequate knowledge, lack of confidence and stigmatising attitudes of healthcare professionals (HCPs) may lead to suboptimal care. Aim: To review the literature exploring HCPs’ knowledge, confidence and attitudes in relation to psychosis care. Method: A systematic search was undertaken across three databases (MEDLINE, Embase, PsycINFO) using a search strategy encompassing the concepts: ‘healthcare professionals’, ‘knowledge, attitude, and confidence in care’ and ‘psychotic illnesses and symptoms’ to identify relevant records published from 1st January 2002 to 18th March 2022. Results were screened against predetermined inclusion and exclusion criteria by title and abstract, followed by full text. Data were extracted into tables and synthesised narratively. Results: Initially, 7,397 studies were identified. Following two-stage screening, 24 studies were eligible for inclusion. Of these studies, 16 explored attitudes, four explored knowledge and attitudes, one explored knowledge, one explored confidence, one explored attitudes and confidence in care and one explored all three constructs. Most HCPs in the included studies demonstrated stigmatising attitudes towards people with psychosis. Furthermore, certain HCPs, including nurses and general practitioners, demonstrated low levels of knowledge, while psychiatrists, occupational therapists, psychologists and nurses had low levels of confidence in caring for people with psychosis. Conversely, positive attitudes were also observed in some HCPs resulting from having acquaintances with lived experience of psychosis. The need for additional education and training to improve HCPs’ knowledge and confidence in relation to caring for people living with psychosis was identified. Conclusions: Most attitudes identified were negative and stemmed from stigma, while some were positive due to HCPs’ compassion and familiarity with psychosis. The level of knowledge and confidence identified were mostly suboptimal, and so further research is required to develop and evaluate tailored interventions to address this gap.