The morphology and thermal properties of PHBV/PHO/starch blends are investigated using polarized optical microscopy, differential scanning calorimetry, thermal gravimetric analysis, and X-ray diffraction. The crystallization behavior of the PHBV in PHBV/PHO was improved via the incorporation of a biodegradable nucleating agent, starch, as indicated by thermal analysis and polarized optical micrographs. The PHBV and PHO show phase separation in the blend. The XRD patterns of PHBV in blends are identical to those of neat PHBV. The Avrami exponents were not considerably impacted by the presence of PHO or starch. Furthermore, the nucleation constant, Kg, of the PHBV blends was evaluated using a modified Lauritzen–Hoffmann treatment. The Kg values indicated that the crystallization of PHBV in all blends occur in Regime III. PHO and starch have little impact on the maximum degradation temperature of PHBV.