配子体（英文：gametophyte）为行世代交替的植物及藻类中，处于单倍体的多细胞阶段。配子体会进行有丝分裂产生配子（可能是雄配子、雌配子或两者皆产生，依种类不同）。配子结合后产生合子 (zygote)，合子会行有丝分裂长成双倍体多细胞的孢子体个体。孢子体成熟后，会经由减数分裂产生单倍体的孢子，孢子再度行有丝分裂生长形成配子体个体，完成世代交替的循环。

在苔藓植物（地钱门、角苔门及苔藓植物门）中，配子体为较明显可辨认的阶段，由孢子萌发后，经由原丝体的阶段生长而来（角苔的配子体发育过程中未经过原丝体的阶段）；苔藓的孢子体必须依附于配子体上以获取养分。苔藓植物配子体上生产配子的器官称为配子囊 (gametangium)。

A gametophyte is a stage in the life cycle of plants and algae that undergo alternation of generations. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote in which each cell has two sets of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte, the function of which is to produce haploid spores by meiosis.