IMPORTANCE: Obese subjects with obstructive sleep apnea (OSA) are at risk of pulmonary hypertension (PH) and mortality. Positive airway pressure (PAP) treatment lowers pulmonary artery pressures and mortality risk. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduces body weight and cardiovascular risk, but their effectiveness in OSA remains unexplored. OBJECTIVE: To assess whether GLP-1 RAs is associated with lower incident PH and all-cause mortality at 1 and 3 years in obese patients with OSA treated with PAP. DESIGN: Retrospective cohort study. SETTING: US Collaborative TriNetX Global Database analysis performed on January 5, 2026 encompassing data from 56 centers during December 1, 2017 and December 25, 2025. PARTICIPANTS: Obese patients diagnosed with OSA and treated with PAP (n=288,587). EXPOSURE: Propensity score-matched comparisons of PAP vs PAP+semaglutide, PAP vs PAP+tirzepatide, PAP+semaglutide vs PAP+tirzepatide. MAIN OUTCOMES AND MEASURES: Incident PH and all-cause mortality at 1 and 3 years. Risk ratios (RRs) with 95% CIs were estimated using the delta method; number needed to treat (NNT) was calculated from the absolute risk difference. RESULTS: Compared with PAP, PAP+semaglutide was associated with lower incident PH at 1 year (RR:0.45; 95% CI:0.44–0.56, NNT=38) and at 3years (RR:0.50; 95% CI:0.45–0.54, NNT=23), and lower mortality at 1 year (RR:0.35; 95% CI:0.33–0.37, NNT=12) and 3 years (RR:0.37; 95% CI:0.35–0.39, NNT=8); PAP+tirzepatide was associated with lower incident PH at 1 year (RR:0.27; 95% CI:0.22–0.34, NNT=28) and 3 years (RR:0.22; 95% CI:0.18–0.27, NNT=15) and lower mortality at 1 year (RR:0.14; 95% CI:0.12–0.17, NNT=9) and 3 years (RR:0.12; 95% CI:0.10–0.14, NNT=6). Compared to PAP+semaglutide, PAP+tirzepatide showed lower incident PH at 1 year (RR:0.51; 95% CI:0.40–0.65, NNT=77) and 3 years (RR:0.42; 95% CI:0.34–0.51, NNT=39) and lower all-cause mortality at 1 year (RR:0.41; 95% CI:0.34–0.49, NNT=40) and 3 years (RR:0.33; 95% CI:0.28–0.39, NNT=22); all p-values<0.001. CONCLUSIONS AND RELEVANCE: Obese-OSA patients treated with PAP taking GLP-1RAs exhibited significantly lower 1-year and 3-year incident PH and all-cause mortality versus PAP. Tirzepatide exhibited further lowering of incident PH and all-cause mortality versus semaglutide, showing increased and sustained benefits over time. KEY POINTS: Question: Among patients with obesity and obstructive sleep apnea (OSA) treated with positive airway pressure (PAP), is use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) associated with lower incident pulmonary hypertension (PH) and all-cause mortality at 1 and 3 years? Findings: In a cohort study of 288,587 patients, PAP plus semaglutide or tirzepatide was associated with significantly lower incident PH and all-cause mortality versus PAP alone at 1 and 3 years. Tirzepatide was associated with lower risks than semaglutide. Meaning: GLP-1 RAs may provide additional clinical benefit in obese patients with OSA treated with PAP.