Spirodela polyrrhiza (L.) Schleid. (giant duckweed)—a widespread aquatic macrophyte was found to be a potential chromium bioaccumulator in the present study. To assess the tolerance and hyperaccumulation of chromium by S. polyrrhiza, the plants were exposed to 25, 50, 75, and 100% concentrations of tannery effluent under laboratory conditions for 7 days. Significant toxic effects on the S. polyrrhiza plant were observed, as revealed by reduction in growth parameters as well as photosynthetic pigments in comparison to the control. Despite exhibiting severe phytotoxicity symptoms, the roots and fronds of S. polyrrhiza accumulated the highest amount of chromium on exposure to 100% tannery effluent (roots: 64,841.8 mg g−1; fronds: 10,478.4 mg g−1) after 7 days of exposure. Our results point to S. polyrrhiza as a proficient species to be used in the exploration of chromium hyperaccumulation as well as a prospective contender for tannery wastewater remediation.