在植物学和园艺学上，单性结实（英语：Parthenocarpy）是指天然或人工作用下使胚珠不经授粉而结果的现象。在胚珠未经受精的情况下，子房产生发育而形成无籽果实（Seedless fruit）。与种子败育（Stenospermocarpy）不同，单性结实发育出来的果实是真正无籽的；而通过种子败育发育出来的果实，事实上只是由于在种子很小的时候发生了胚胎放弃，而使得种子保持在了很小和败育的状态而已。

单性结实像种子败育一样，偶尔也会在自然界以突变的形式出现。出现单性结实的个体无法经由有性生殖繁殖，但仍可借由无性生殖的方式产生后代。

In botany and horticulture, parthenocarpy (literally meaning virgin fruit) is the natural or artificially induced production of fruit without fertilization of ovules. The fruit is therefore seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds are actually aborted while still small. Parthenocarpy (or stenospermocarpy) occasionally occurs as a mutation in nature; if it affects every flower the plant can no longer sexually reproduce but might be able to propagate by apomixis or by vegetative means.