核酮糖-1,5-二磷酸（英语：ribulose-1,5-bisphosphate，缩写RuBP）又称为1,5-二磷酸核酮糖、二磷酸核酮糖、双磷酸核酮糖，是在光合作用中的卡尔文循环里起重要作用的一种五碳糖。植物体内的酶用RuBP作为底物来固定二氧化碳，生成六碳磷酸盐，这种高度不稳定的中间产物最终分解为两分子的磷酸甘油酸。

Ribulose-1,5-bisphosphate (RuBP) is an organic substance that is involved in photosynthesis. It is a colourless anion. a double phosphate ester of the ketose (ketone-containing sugar) called ribulose. Salts of RuBP can be isolated, but its crucial biological function happens in solution. To simplify the presentation, the image in the above table depicts the acid form of this anion.