Background: Obstructive sleep apnea (OSA) is commonly associated with pharyngeal airway collapse during sleep. Anterolateral advancement (ALA) pharyngoplasty is a modern surgical technique designed to improve retro palatal airway stability. Objective: To evaluate the effectiveness of ALA pharyngoplasty across different pharyngeal collapse patterns in adult patients with OSA. Methods: A systematic review was conducted following PRISMA guidelines. Studies published between 2015 and 2025 evaluating ALA pharyngoplasty with preoperative assessment using drug-induced sleep endoscopy (DISE) were included. Outcomes included apnea–hypopnea index (AHI), Epworth Sleepiness Scale (ESS), oxygen saturation, and airway dimensions. Results: Nineteen studies were included in the final analysis. Across studies, AHI decreased from approximately 32–48 events/hour preoperatively to 9–14 events/hour postoperatively. ESS improved by approximately 7–11 points, and significant increases in posterior airway space and oxygen saturation were reported. Improvements were observed across anteroposterior, lateral, and concentric collapse patterns, although patients with concentric collapse demonstrated smaller postoperative gains. Conclusion: ALA pharyngoplasty appears to provide meaningful clinical and anatomical improvement in patients with OSA across different collapse phenotypes. However, the available evidence remains heterogeneous and largely observational, highlighting the need for standardized protocols and long-term prospective studies.