Seljuk (Ottoman Turkish: سلجوق, Selcuk) or Saljuq (Arabic: سلجوق, Saljūq) may refer to:

• Seljuk Empire (1051–1153), a medieval empire in the Middle East and central Asia
• Seljuk dynasty (c. 950–1307), the ruling dynasty of the Seljuk Empire and subsequent polities
• Seljuk (warlord) (died c. 1038), founder of the Seljuk dynasty
• Seljuk Sultanate of Rum (1077–1308), a medieval empire founded by later members of the dynasty