Background: Sickle Cell Disease (SCD) presents significant health challenges globally. Despite its prevalence in diverse geographical regions, there is a paucity of literature synthesizing evidence on healthcare professionals’ knowledge, attitudes, and practices (KAP) toward SCD assessment and management. This meta-aggregative review systematically examined and synthesized existing qualitative research to elucidate healthcare professionals’ KAP regarding SCD assessment and management. Methods: This meta-aggregative review followed Aromataris and Pearson’s guidelines and the PRISMA framework for systematic review reporting. The search was conducted in Scopus, PubMed, Embase, CINAHL Web of Science, Google Scholar, Dimensions AI, and HINARI. Quality appraisal was performed using the Joanna Briggs Institute tool. Results: Healthcare professionals (HCPs) demonstrate varying levels of KAP toward SCD assessment and management. Studies reveal low-to-moderate levels of general knowledge among HCPs, with nurses often exhibiting poorer understanding than physicians. Deficiencies in awareness of specific interventions, such as chemoprophylaxis and prenatal diagnosis, are noted, along with gaps in SCD assessment and diagnosis, particularly in pain management and premarital screening. Attitudes toward SCD patients vary, and practices reveal inconsistencies and deficiencies, including inadequate nutritional counseling and barriers in emergency departments. However, interventions aimed at improving HCPs’ KAP show promise in enhancing understanding and attitudes toward SCD, suggesting potential avenues for improvement. Conclusions: Educational initiatives targeted at both student nurses and practicing healthcare providers, coupled with the implementation of standardized protocols and guidelines, can enhance knowledge acquisition and promote consistent, high-quality care delivery. Future studies should improve the quality of their methods in this area of study.