Background: Carbon tetrachloride (CCl4) is a toxic heavy liquid used in industry, known as a hepatotoxic agent. It also leads to nephrotoxicity, compromising kidney function by triggering oxidative stress and inflammatory responses. Moreover, the identification of a natural, safe material capable of attenuating CCl4-induced nephrotoxicity would be valuable for therapeutic purposes. Purpose: This study investigated the potential renoprotective effects of secoisolariciresinol diglucoside (SDG), a naturally occurring antioxidant in flaxseed, against nephrotoxicity induced by carbon tetrachloride (CCl4) in a rat model. Methods: “Four groups of albino Wistar rats were treated with saline, SDG, CCl4, and CCl4 followed by SDG, respectively. Body weight, serum creatinine, urea, and albumin levels were measured, and the activities of antioxidant enzymes were determined. Kidney tissue samples were also subjected to histopathological examinations. Results: Histopathological investigations demonstrated that administration of CCl4 caused increases in serum creatinine and urea levels, along with a decrease in antioxidant enzyme activity and albumin, confirming the induction of nephrotoxicity. Concurrent treatment with SDG reduced these effects, as indicated by improved biochemical parameters, increased activity of antioxidant enzymes, and decreased histopathological changes in kidney tissue sections.