Unity Day
National Unity Day, Union Day, Unification Day may refer to:
National unification
Alphabetic by country.
- National Unity Day (Belarus), a holiday in Belarus on September 17
 - Unification Day (Bulgaria), a holiday in Bulgaria on September 6
 - Unity Day (Burundi), a holiday in Burundi on February 5
 - National Unity Day, a holiday in Georgia on April 9
 - National Unity Day, a holiday in Hungary on June 4
 - German Unity Day, a holiday in Germany on October 3
 - National Unity Day (India), a holiday in India on October 31
 - Kazakhstan People's Unity Day, a holiday in Kazakhstan on May 1
 - Great Union Day, a holiday in Romania on December 1
 - Unity Day (Russia), a holiday in Russia on November 4
 - Unity Day (Tajikistan), a holiday in Tajikistan on June 27
 - Day of Unity of Ukraine, a holiday in Ukraine on January 22
 - Unity Day (United States), a holiday in the United States in October
 - Unity Day (Vanuatu), a holiday in Vanuatu on November 29
 - Unity Day (Yemen), a holiday in Yemen on May 22
 - Unity Day (Zambia), a holiday in Zambia on the day after Heroes' Day
 - Unity Day (Zimbabwe), a holiday in Zimbabwe on December 22
 
Community unity celebrations
- Unity Day (Leeds), a free open air festival in Leeds in early August
 - Unity Day (Philadelphia), a celebration in August in Philadelphia