Background and Objectives: As adjuvant treatment for human epidermal growth factor receptor 2 (HER2)-negative early-stage breast cancer (eBC) evolves, real-world data should inform olaparib utilization, sequencing, and combination patterns in clinical practice. Methods: Using Komodo US claims data (1 January 2019–31 December 2023), we retrospectively analyzed HER2-negative eBC patients on adjuvant olaparib. Continuous insurance for 12 months pre- and ≥30 days post-index date (first olaparib prescription), with follow-up through disenrollment or study end, was required. Outcomes, including time on therapy (Kaplan–Meier median persistence), adherence (proportion of days covered), dose reduction, and combination patterns, were stratified by claims-derived hormone-receptor-positive (HR+) and triple-negative BC (TNBC) status. Results: Among 176 olaparib-treated patients (median age, 44 years), the median (95% CI) time on therapy was 11.0 (9.2, 12.2) months; 27.3% (n = 48) discontinued before 12 months without re-initiating, 19.9% experienced a dose reduction, and median adherence was 90%. Olaparib was combined with other therapies in 48.3% (n = 85) (29.6% [32/108] of TNBC and 77.9% [53/68] of HR+ patients), most often with immunotherapy in TNBC (81.3%, n = 26) and endocrine therapy in HR+ (88.7%, n = 47). Conclusions: Real-world data suggest favorable persistence and dosing patterns with adjuvant olaparib. Future research should prioritize olaparib combination regimen safety and effectiveness.