NLL may refer to:

Sports

• Two unrelated lacrosse leagues by the name of National Lacrosse League:
  • National Lacrosse League, an ongoing league formed in 1987
  • National Lacrosse League (1974–75), a defunct league formed in 1974
• Northern Lakes League, a Northwest Ohio High School athletic conference
• Nación Lucha Libre, a Mexican professional wrestling promotion

Politics

• Northern Limit Line, a disputed maritime boundary between North and South Korea
• National Liberation League in Palestine, a defunct political party in Palestine

Institutions

• New Line Learning Academy, a school in Loose, England
• The National Library of Latvia
• Foundation NLL, a former name of the Royal Netherlands Aerospace Centre

Transportation

• The North London Line, a railway line in London, England