Tree may refer to:

• A woody biological organism
• Things shaped like trees, such as:
  • Evolutionary tree
  • Tree (graph theory)
  • Hierarchical organization
  • Tree data structure
  • biblical Tree of life
  • A family tree, which is a chart in genealogy.
  • A shoe tree, which is a device for storing shoes.
• A colloquial term for certain instruments of execution, notably the cross and the gallows
• TREE Trends in Ecology and Evolution is a scientific journal
• Tree is the pronunciation of the digit 3 in the NATO phonetic alphabet.