Cell junctions or junctional complexes are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. Combined with cell adhesion molecules and extracellular matrix, cell junctions help hold animal cells together.

In vertebrates, there are three major types of cell junction:

The analogues of communicative cell junctions in plants are called plasmodesmata.