We report on the effect of blending poly L-(lactide) (PLLA) and poly(3-hydroxybutyrate-co-3-hydroxydecanoate) (PHBD). PHBD was obtained from bacterial fermentation with brewer’s spent grains in recombinant E. coli co-fed fatty acid. Films were prepared by solvent casting using dichloromethane. We prepared films with varying weight percentages of PLLA and PHBD. All films were characterized by Attenuated Total Reflectance- Fourier Transform Infrared Spectroscopy (ATR-FTIR), IR microscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), x-ray diffraction (XRD), and optical microscopy. The film composed of 75 wt%/25 wt% (PLLA/PHBD) exhibited tensile stress (44.5 MPa) and strain at break (10.7%) higher than the values exhibited by neat PLLA films. This behavior was attributed to the PHBD acting as a reinforcing agent and as an enabler of greater intermolecular interactions. We also found that a 25/75 (PLLA/PHBD) film exhibited a water contact angle (WCA) of 125.9˚, which is higher than that of the neat PLLA film, and strong oleophobic behavior. We noted that increasing PHBD content led to greater WCA and oleophobic films. TGA thermograms revealed the blends’ multistep decomposition, with a decreasing onset degradation temperature as PHBD content increased. ATR-FTIR, IR microscopy, and DSC analysis indicated that partial miscibility was achieved in the 75/25 blend, whilst films with greater than 50 wt% PHBD content exhibited crystalline phase separation. Our results highlight the thermal and mechanical complexities of the PLLA/PHBD polymer blends and can open an avenue for the development of films with potential for biobased single-use packaging applications.