Other references are:

• A mathematical concept: see union (set theory)
• A political entity of states: see personal union
• The Northern side in the American Civil War (see Union (American Civil War))
• A type of commercial entity: see union (commerce)
• A trade union (labor union) is a workers' organisation designed to assist in employment negotiation.
• Union (computer science) data type
• Civil union - a commitment ceremony similar to but legally distinct from marriage
• A common place name (especially in the United States of America):
  • Union, Kentucky
  • Union, Maine
  • Union, Mississippi
  • Union, Missouri
  • Union, New Jersey
  • Union, Ohio
  • Union, Oregon
  • Union, South Carolina
  • Union, Wisconsin
  • Union City, California
  • Union City, Georgia
  • Union City, Michigan
  • Union City, New Jersey
  • Union City, Ohio
  • Union City, Pennsylvania
  • Union City, Tennessee
  • Union County, New Jersey
  • Union Township, Michigan
  • Union Township, New Jersey
  • Union Township, Pennsylvania
  • Union, Saint Vincent
  • Union, Grenadines (in the Carribean)