Objectives: This study aimed to systematically review the knowledge, attitudes, and practices (KAP) regarding infection control among clinical dental hygienists in Korea. Methods: Comprehensive searches were conducted across domestic and international databases (including Public MEDLINE [PubMed] and Regional Information Sharing Systems [RISS]) for studies published up to May 1, 2026. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, 36 studies were selected. Study quality was evaluated using a critical review form. To ensure comparability, the extracted scores were standardized using a 5-point Likert scale, and practice domains were categorized based on the Center for Disease Control (CDC) guidelines. Results: Knowledge and awareness levels showed an upward trend. Overall practice levels were reported to be relatively higher following the introduction of the dental healthcare accreditation system in 2017. However, significant variations persisted across specific practice domains. Notably, medical waste management yielded the highest mean scores (3.83–4.75). Conversely, practitioner self-protection indicators, including check-up and vaccination scores (2.85–3.00) and apron application rates (1.1–45.1%), showed the lowest levels, revealing a marked imbalance in infection control implementation. Conclusions: Despite high levels of knowledge regarding infection control, self-protection practices among dental hygienists remain inadequate. To overcome the limitations of the current system, motivation-centric education should be coupled with robust institutional and financial support frameworks such as dental infection prevention and control fees.