Biodegradable starch (Str) polymer was derived from potato, a plant-based natural carbohydrate polymers source, by one-pot synthesis. Hydroxyapatite (HA) was produced from goat bone by step sintering. The inexpensive starch/HA thin film composites were fabricated by customized spin coating. This study revealed that the hydrogen bond energy and distance have significant effect on glass transition temperature of the polymer. The 40 wt % HA contained starch (StrHA40) composite thin film showed excellent tensile strength (3.03 + −0.03 MPa), elongation (21.5 + −5.5%) and modulus (15.5 + −0.2 MPa) closed to human skin. The in vitro swelling and biodegradation kinetics of pristine starch and pure HA has been controlled and improved by using suitable composition. This study postulated the probable water molecule-adsorption mechanisms of pristine starch and starch/HA composite films. The StrHA40 composite showed excellent biocompatibility to the human-blood derived lymphocyte cells. Therefore, the starch/HA thin film composite-based biodegradable scaffolds developed in the present study can be an excellent potential candidate for soft tissue regeneration and/or replacement applications.