在数理逻辑中，霍恩子句（Horn Clause）是带有最多一个肯定文本的子句(文本的析取)。霍恩子句得名于逻辑学家 Alfred Horn，他在 1951 年首先在文章《On sentences which are true of direct unions of algebras》, Journal of Symbolic Logic, 16, 14-21 中指出这种子句的重要性。

有且只有一个肯定文本的霍恩子句叫做明确子句，没有任何肯定文本的霍恩子句叫做目标子句。霍恩子句的合取是合取范式，也叫做 霍恩公式。霍恩子句在逻辑编程中扮演基本角色并且在构造性逻辑中很重要。

In mathematical logic and logic programming, a Horn clause is a logical formula of a particular rule-like form which gives it useful properties for use in logic programming, formal specification, and model theory. Horn clauses are named for the logician Alfred Horn, who first pointed out their significance in 1951.