Lojban (pronounced [ˈloʒban]) is a constructed, syntactically unambiguous human language, succeeding the Loglan project.

The Logical Language Group (LLG) began developing Lojban in 1987. The LLG sought to realize Loglan's purposes, and further improve the language by making it more usable and freely available (as indicated by its official full English title, "Lojban: A Realization of Loglan"). After a long initial period of debating and testing, the baseline was completed in 1997, and published as The Complete Lojban Language. In an interview in 2010 with the New York Times, Arika Okrent, the author of In the Land of Invented Languages, stated: "The constructed language with the most complete grammar is probably Lojban—a language created to reflect the principles of logic."