This study was conducted to evaluate the effectiveness of phosphorus P-solubilizing purple nonsulfur bacteria, Cereibacter sphaeroides ST16 and ST26, on improving soil quality, nutrient uptake, growth, and yield of rice farmed in salinized soil in the rice-shrimp system. A two-factor experiment was arranged in completely randomized blocks with four replications. Factor (A) represented P fertilizing rates, including 0%, 25%, 50%, 75%, and 100% P as the recommendation. Factor (B) consisted of the negative control (NC), a strain of C. sphaeroides ST16, C. sphaeroides ST26, and the mixture of ST16 and ST26. The results indicated that using the ST16-ST26 mixture decreased Na⁺ concentration by 15.2–21.1%, improved soluble P content by 11.5–21.0%, and reduced contents of Fe-P by 14.8–15.1%, Ca-P by 6.18–22.5%, and Al-P by 4.55–8.58%. Additionally, a single or the mixture application increased the total P uptake by 16.7–37.0% and decreased the total Na uptake by 6.12–17.2%, as compared with NC. In addition, fertilizing 100% P developed rice grain yield by 26.1–34.7% as compared with the 0% P applied. Simultaneously, using the ST16-ST26 mixture elevated the rice grain yield by 10.7–25.0%, chlorophyll content, and lowered proline content as compared with NC.