BUJ, B.U.J, or buj can refer to:

• Bou Saada Airport, an airport near Bou Saada, Algeria
• Bowj (also spelled "Buj"), a village in Kerman province, Iran
• Bovaj (also spelled "Buj"), a village in South Khorasan province, Iran
• Buj, a village in Hungary
• Burton Joyce railway station, a train station in Burton Joyce, Nottinghamshire, England, U.K.
• Baccalaureus Utriusque Juris (abbreviated B.U.J.), an abbreviation meaning "Bachelor of Both Laws" (i.e. both civil law and canon law); see List of classical abbreviations
• Koromba language, a language spoken in Nigeria, by ISO 639 code