TLG may refer to:

• Tea Leaf Green, a band
• The Lego Group, a company that manufactures LEGO toys
• The Lion Guard, an animated TV series
• The Little Gym, an international franchise of children's gyms
• The Livingston Group, a lobbying firm based in Washington, D.C.
• The Lying Game, a TV series
• Thesaurus Linguae Graecae, a research centre at the University of California
• Tiger Leaping Gorge, a canyon in China
• Top Level Group, a parliamentary group in the United Kingdom
• Trilegiant Corporation, a subsidiary of the Affinion Group
• Troll Lord Games, a publisher of games
• The Limits to Growth, a 1972 computer model of exponential economic growth with finite resources