在集合论和有关的数学分支中，给定集合 S 的子集的搜集 F 叫做 S 的子集族或 S 上的集合族。更一般的说，无论什幺任何集合的搜集都叫做集合族。

• 幂集 P(S) 是在 S 上的集合族。
• n 元素集合 S 的 k 元素子集 S 形成了集合族。
• 抽象单纯复形是集合族。
• 所有序数的类 Ord 是“大”集合族；它自身不是集合而是真类。
• 样本空间的某些子集组成的集合叫做集合族。

In set theory and related branches of mathematics, a collection F of subsets of a given set S is called a family of subsets of S, or a family of sets over S. More generally, a collection of any sets whatsoever is called a family of sets.

The term "collection" is used here because, in some contexts, a family of sets may be allowed to contain repeated copies of any given member, and in other contexts it may form a proper class rather than a set.