To evaluate the effect of local parathyroid hormone (PTH) administration on rotator cuff tendon‐to‐bone healing in a rat model compared with systemic PTH injection and untreated controls. PTH‐alginate scaffold was prepared and sustained release of PTH was confirmed. Bilateral supraspinatus tendon repairs were performed in 39 rats (group 1, supraspinatus repair only;​ group 2, supraspinatus repair with systemic PTH injection;​ group 3, supraspinatus repair with local PTH administration via an absorbable scaffold;​ n = 13 each). Biomechanical (cross‐sectional area, mode of failure, load to failure, and ultimate stress:​ right side) and histological analyses (hematoxylin and eosin stain, Masson's Trichrome stain Picrosirius red stain, Immunohistochemistry for BMP2, PTH1R, ColI, and ColIII:​ Left side) were performed to evaluate tendon‐to‐bone healing quality at 8 weeks after repair, and blood test (osteocalcin and procollagen type I N‐terminal pro‐peptide [PINP] levels) was performed in all rats. There was no intergroup difference in the healing failure rate (p = 0.910) or failure mode (p = 0.585). Biomechanically, subjects in groups 2 and 3 exhibited significantly larger cross‐sectional areas and higher ultimate failure loads and ultimate stress than those in group 1 (all p < 0.05);​ however, no differences were noted between groups 2 and 3 (all p > 0.05). Histologically, groups 2 and 3 exhibited more organized tendon‐to‐bone interface structures with higher density, parallel orientation, and collagen fiber continuity than group 1 (all p < 0.05 except collagen fiber continuity in group 1 vs. 2);​ however, no differences in histological parameters between groups 2 and 3 (all p > 0.05). The protein levels of bone morphogenic protein 2, PTH 1 receptor, and collagen I and III and the serum level of PINP were increased in groups 2 and 3 versus group 1 (all p < 0.05) without showing differences between groups 2 and 3 (all p > 0.05). Local PTH administration using an absorbable scaffold improved the biomechanical and histological outcomes of rotator cuff tendon‐to‐bone healing comparable with systemic PTH injection at 8 weeks after repair in a rat model.