The non-polar aromatic backbone of the fuel cell membrane polyetheretherketone (PEEK) exhibits hydrophobic characteristics which limits adhesion and transport of protons important for the generation of clean energy in hydrogen fuel cells. Therefore, PEEK was treated with vacuum UV (VUV) (λ = 104.8 and 106.7 nm) photo-oxidation, using a microwave (MW) plasma of Ar as the radiation source, to increase wettability of the surface. X-ray photoelectron spectroscopy (XPS) detected an increase in the atomic % (at%) of oxygen up to 20 at% due to an increase in the presence of C-O, C=O, and O-C=O/O=C-OH functional groups. Oxidation of the surface enhanced wettability, as determined by water contact angle (CA) measurements, showing a decrease from 80.3°, for untreated PEEK, down to 45.1°. Little change in surface roughness was observed by Atomic Force Microscopy (AFM). Washing the treated saturated surface with ethanol solvent increased the CA back to near the value for untreated PEEK indicating the formation of a weak boundary layer.