Antarctica is the continent with the lowest local human impact, yet it is still vulnerable to contaminants coming from external sources. Emerging pollutants, like PFAS, pose an increasing threat to this environment and therefore require more in-depth investigations to understand their environmental fate and biological impacts. The present study, part of the AntaGPS project, focuses on expression analysis at the transcriptional level of genes coding for 4 antioxidant enzymes (sod1, sod2, gpx1, gpx4) in different organs of an Antarctic fish species, Trematomus newnesi. The kidney showed a higher level of expression than the liver of wildlife specimens. The mRNA levels were also assessed in fish exposed to 1.5 μg/L of PFOA for 10 days. In the liver, the treatment induced an increase in gene expression for all the considered enzymes, while in the kidney it induced a general decrease. The obtained results constitute a starting point for using the expression of antioxidant enzymes as biomarkers, both of oxidative stress and exposure to PFAS, in future biomonitoring campaigns in the Antarctic marine environment.