Changes in atmospheric composition will greatly alter future rice production. In this study, a new closed-top chamber was used to investigate the effects of elevated CO₂ and O₃ on growth, dry matter production, and nitrogen (N) uptake. A three-line indica hybrid rice cultivar, Shanyou 63, was grown under five gas treatments: ambient, CK (realtime simulation of ambient conditions), elevated [O₃] (60% higher than the ambient O₃ concentration), elevated [CO₂] (200 μmol/mol above ambient CO₂ concentration), and combined elevation of [CO₂+O₃]. For most of the measured parameters, there was no statistically significant difference between ambient and CK plants. Relative to the CK, elevated [O₃] was significantly related to decreased plant height and tiller number within the middle and late growth stages, with the largest decreases (21% for plant height and 15% for tiller number) detected at the final measurements. Elevated [CO₂] showed opposite trends, with the largest ozone-induced increases of 5% and 18% for plant height and tiller number, respectively. Elevated [CO₂+O₃] decreased plant height (largest reduction: 7%), but did not alter tiller number. Compared with the CK, elevated [O₃] greatly decreased the biomass of leaves, stems, panicles, and roots at grain maturity, with 51% reduction recorded for total biomass. Elevated [CO₂] did not change the biomass of green and senescent leaves, but increased the biomass of stems, panicles, roots, and thus total biomass (37%). There was no significant effect of elevated [CO₂+O₃] on total biomass and its components. Dry matter distribution in leaves significantly increased with elevated [O₃], while opposite trends were observed with elevated [CO₂]. The magnitude of the combined [CO₂+O₃] effect on dry matter distribution was smaller than that of the solo [O₃] treatment. Elevated [O₃] increased shoot N concentration by 29%, and it decreased shoot N uptake by 31% at heading stage. Elevated [CO₂] and [CO₂+O₃] had no significant effect on aboveground N concentration and uptake. The above results suggested that the projected increase of surface ozone concentration will inhibit plant elongation, tiller production, and growth of hybrid Shanyou 63. The concurrent increases in [CO₂+O₃] either ameliorated or negated the detrimental effects of O₃ stress on growth and development.