ITIL, formerly an acronym for Information Technology Infrastructure Library, is a set of practices for IT Service Management (ITSM) that focuses on aligning IT services with the needs of business. In its current form (known as ITIL 2011 edition), ITIL is published as a series of five core volumes, each of which covers a different ITSM lifecycle stage. Although ITIL underpins ISO/IEC 20000 (previously BS15000), the International Service Management Standard for IT service management, there are some differences between the ISO 20000 standard and the ITIL framework.

Itil may mean:

• Atil or Itil, the ancient capital of Khazaria
• Itil (river), also Idel, Atil, Atal, the ancient and modern Turkic name of the river Volga.