同构基本定理或称同态基本定理，包含三个定理，在泛代数领域有广泛的应用。它们证明了一些自然同构的存在性。

同构基本定理最早由埃米·诺特（Emmy Noether）在她于1927在德国数学期刊数学分析（Mathematische Annalen）发表的论文Abstrakter Aufbau der Idealtheorie in algebraischen Zahl- und Funktionenkörpern中明确阐述。

In mathematics, specifically abstract algebra, the isomorphism theorems are three theorems that describe the relationship between quotients, homomorphisms, and subobjects. Versions of the theorems exist for groups, rings, vector spaces, modules, Lie algebras, and various other algebraic structures. In universal algebra, the isomorphism theorems can be generalized to the context of algebras and congruences.