De facto（拉丁语发音：[deː ˈfaktoː]，英语发音：英语发音：/diːˈfæktoʊ/, 英语发音：/deɪ/），一个拉丁语法律格言，意思指「事实上」或者「运行上」，而法律上并未宣告。与拉丁语的de jure相对—de jure的意思是指「法律上」等由法律、政府干预、技术性的手段（例如规格、标准、协议等）等明文规定的方法，而de facto的意义则着重于该方法是由通俗的经验所构成，不由规范所构成，甚至方法本身亦与规范互相违反。当发生于法律上的情况时，de jure表明法律上的明文规定，而de facto则表明实际运作上的方法和行为。

De facto (/dᵻ ˈfæktoʊ/, /deɪ-/, Latin: [deː ˈfaktoː]) is a Latin expression that means "in fact, in reality, in actual existence, force, or possession, as a matter of fact" (literally "of fact"). In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established". It is commonly used in contrast to de jure (which means "according to (the) law"; literally "from law") when referring to matters of law, governance, or technique (such as standards) that are found in the common experience as created or developed without or contrary to a regulation. When discussing a legal situation, de jure designates what the law says, while de facto designates action of what happens in practice.