De jure (, ; Classical Latin: de iúre ) is an expression that means "of right, by right, according to law" (literally "from law"), as contrasted with de facto, which means "in fact, in reality" (literally "from fact"). The terms de jure and de facto are used instead of "in law" and "in practice", respectively, when one is describing political or legal situations.
In a legal context, de jure is contrasted to de facto practices, where, for example, the people obey a contract as though there were a law enforcing it, yet there is no such law. A process known as "desuetude" may allow (de facto) practices to replace (de jure) laws that have fallen out of favor, locally.
It is possible to have multiple simultaneous conflicting (de jure) legalities, possibly none of which is in force (de facto). After seizing power in 1526, Ahmad ibn Ibrahim al-Ghazi made his brother, Umar Din, the lawful (de jure) Sultan of Adal. Ahmad, however, was in practice (de facto) the actual Sultan, and his brother was a figurehead. Between 1805 and 1914, the ruling dynasty of Egypt ruled as de jure viceroys of the Ottoman Empire, but acted as de facto independent rulers who maintained a polite fiction of Ottoman suzerainty. However, from about 1882, the rulers had only de jure rule over Egypt, as it had by then become a British puppet state. Thus, Egypt was by Ottoman law de jure a province of the Ottoman Empire, but de facto was part of the British Empire.
In American law, particularly after Brown v. Board of Education (1954), the difference between de facto segregation (segregation that existed because of the voluntary associations and neighborhoods) and de jure segregation (segregation that existed because of local laws that mandated the segregation), became important distinctions for court-mandated remedial purposes.
In Canada, cannabis is illegal in law, but there is widespread use in practice, especially in British Columbia. It is strikingly similar to the existence of speakeasies during prohibition, wherein enforcement of laws departed from the letter, because of widespread and popular practice.
- See I. 5.