在数学中，张量积，记为 ，可以应用于不同的上下文中如矢量、矩阵、张量、矢量空间、代数、拓扑矢量空间和模。在各种情况下这个符号的意义是同样的: 最一般的双线性运算。在某些上下文中也叫做外积。

例子:

结果的秩为1，结果的维数为 4×3 = 12。

这里的秩指示张量秩（所需指标数），而维数计算在结果数组(阵列)中自由度的数目；矩阵的秩是 1。

代表情况是任何两个被当作矩阵的矩形数组的克罗内克积。在同维数的两个矢量之间的张量积的特殊情况是并矢积。

In mathematics, the tensor product, denoted by ⊗, may be applied in different contexts to vectors, matrices, tensors, vector spaces, algebras, topological vector spaces, and modules, among many other structures or objects. In each case the significance of the symbol is the same: the freest bilinear operation. In some contexts, this product is also referred to as outer product. The general concept of a "tensor product" is captured by monoidal categories; that is, the class of all things that have a tensor product is a monoidal category. The variant of ⊗ is used in control theory.