Background/Objectives: Minimally invasive cardiac surgery is often avoided in patients with obesity due to exposure and surgical access concerns. Nonetheless, these patients have elevated periprocedural risks. Minimally invasive transaxillary aortic valve surgery offers a sternum-sparing "nearly no visible scar" alternative to the traditional full sternotomy. This study evaluated the clinical outcomes of patients with obesity compared to a propensity score-matched full sternotomy cohort. Methods: This retrospective cohort study included 1086 patients with obesity (body mass index [BMI] of >30 kg/m2) undergoing isolated aortic valve replacement from 2014 to 2023. Two hundred consecutive patients who received transaxillary minimally invasive cardiac lateral surgery (MICLAT-S) served as a treatment group, while a control group was generated via 1:1 propensity score matching from 886 patients who underwent full sternotomy. The final sample comprised 400 patients in both groups. Outcomes included major adverse cardio-cerebral events, mortality, and postoperative complications. Results: After matching, the clinical baselines were comparable. The mean BMI was 34.4 ± 4.0 kg/m2 (median: 33.9, range: 31.0-64.0). Despite the significantly longer skin-to-skin time (135.0 ± 37.7 vs. 119.0 ± 33.8 min; p ≤ 0.001), cardiopulmonary bypass time (69.1 ± 19.1 vs. 56.1 ± 21.4 min; p ≤ 0.001), and aortic cross-clamp time (44.0 ± 13.4 vs. 41.9 ± 13.3 min; p = 0.044), the MICLAT-S group showed a shorter hospital stay (9.71 ± 6.19 vs. 12.4 ± 7.13 days; p ≤ 0.001), lower transfusion requirements (0.54 ± 1.67 vs. 5.17 ± 9.38 units; p ≤ 0.001), reduced postoperative wound healing issues (5.0% vs. 12.0%; p = 0.012), and a lower 30-day mortality rate (1.5% vs. 6.0%; p = 0.031). Conclusions: MICLAT-S is safe and effective. Compared to traditional sternotomy in patients with obesity, MICLAT-S improves survival, reduces postoperative morbidity, and shortens hospital stays.