The effects of graded levels (0–20% total dietary inclusion) of commercial, solvent-extracted soybean meal (SBM) and expeller sunflower meal (SFM) were investigated on growth, nutrient utilization, and pro-inflammatory gene expression in the distal intestine and spleen of two commercial Canadian strains (Strain 1 and Strain 2) of Arctic charr. Five experimental diets with increasing inclusion of SBM or SFM were fed for 84days to two Canadian strains of Arctic charr (initial body weight=9g/fish). Feeding these diets resulted in no differences in growth rate (measured as final weight or thermal-unit growth coefficient, TGC) in the two strains. Increased inclusion level of plant proteins negatively affected FE (P<0.0001) with effects most commonly observed in groups fed SBM-based diets. The effect of the ingredient was significant (P<0.05) on PXR gene expression in the distal intestine; PXR expression was higher with SBM than with SFM. The effect of the inclusion level of plant ingredients was significant (P<0.05) on IL-Iβ gene expression in the spleen. Feed intake, FE, NRE, ERE, whole body crude protein, lipid, gross energy, and organo-somatic indices were significantly (P<0.05) affected by genetic strain examined. Strain 2 exhibited higher FE and carcass crude protein content and lower carcass lipid content. The difference in FE, protein and lipid content for the 2 genetic strains of charr may indicate variations in efficiency for protein and lipid utilization, with a potential protein-sparing effect of dietary lipid noted in Strain 2.