This review aimed to better understand the application of Quality Improvement (QI) processes to increase adherence to safe infant sleep recommendations in inpatient hospital settings. Following Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020 guidelines, we searched MEDLINE/PubMed, CINAHL, and PsycINFO for articles published between 1992 and 2021 describing safe infant sleep QI processes in inpatient settings. Data were extracted from eligible articles based on the hospital setting, intervention target, and QI elements in addition to QI improvement efforts. Article quality was assessed using Standards for Quality Improvement Reporting Excellence (SQUIRE) criteria. The initial search yielded 331 articles; 27 met eligibility criteria for data extraction. QI was conducted in pediatric, maternity, and neonatal intensive care units, or a combination. The most often targeted practices were supine position and no objects in crib, followed by parent teaching, sleep location, flat surface, and appropriate bundling. Change approaches fit four broad categories: staff education, parent education, policy, and unit environment changes. All articles reported at least partial success in increasing adherence, and the “lessons learned” can assist hospital teams in tailoring their own safe sleep QI process.