The aim of the study was to assess the effect of fermented soybean meal (FSBM) and/or rapeseed meal (FRSM) on the redox status of blood and tissues in piglets. The experiment was conducted on 150 28-day-old weaned piglets divided into five groups. Piglets in the control group received standard diets with soybean meal. Animals in the experimental groups received diets in which a portion of the soybean meal was replaced with FRSM and/or FSBM: group FR—8% FRSM; group FR/FS—6% FRSM and 2% FSBM; group FS/FR—2% FRSM and 6% FSBM; and group FS—8% FSBM. Group FR/FS showed an increase in total antioxidant potential of plasma (FRAP) and low-molecular-weight antioxidants, i.e., vitamin C, urea, uric acid, and albumin, as well as an increase in catalase activity. Blood levels of lipid hydroperoxides (LOOH) and malonyl dialdehyde (MDA) were decreased. A reduction in lipid peroxidation due to the use of FR/FS was also indicated by a decrease in liver MDA and jejunum wall LOOH levels. Increases in superoxide dismutase (SOD) and catalase (CAT) activity and vitamin C levels in these tissues were also noted. The results of the study indicate that the inclusion of fermented rapeseed meal in the diet (6%) in combination with soybean meal (2%), improved the redox status of the weaners.