DLL is an abbreviation which can commonly mean:

• Data link layer, a layer in the OSI network architecture model
• Davis-Logemann-Loveland algorithm, an algorithm that solves the Boolean satisfiability problem
• Delay Locked Loop, a device to reduce clock skew in digital circuits
• Doubly-linked list, a data structure in computer programming
• Dynamically linked library in computer science
  • Dynamic-link library, its implementation in Microsoft Windows and OS/2

DLL