There were 104 countries either involved in or affected by World War II.
Virtually every country was involved in one form or another.
Even the neutral counties were harmed by their neighbors being at war and unable to trade as in the past.
If you want a list of combatants Allies and Axis powers their are good reference pages on Wikipedia. (see Related Links)
Albania, Andorra, Argentina, Armenia, Australia, Austria, Azerbaijan, Bahrain, Belarus, Belgium, Bolivia, Brazil, Bulgaria, Canada, Ceylon (Sri Lanka), Chile, China, Colombia,Costa Rica, Croatia, Cuba, Czechoslovakia, Denmark, Dominican Republic, Ecuador, Egypt, El Salvador, Estonia, Ethiopia, Fiji, Finland, France, Georgia, Germany, Gibraltar, Greece, Guatemala, Haiti, Honduras, Hong Kong, Hungary, Iceland, British India (now India, Pakistan & Bangladesh), Indonesia, Iran, Iraq, Ireland, Italy, Japan, Korea, Laos, Latvia, Lebanon, Liberia, Liechtenstein, Lithuania, Luxembourg, Malaya, Malta, Manchukuo, Mexico, Monaco, Mongolia, Morocco, Nauru, Nepal, Netherlands, Newfoundland, New Zealand, Nicaragua, Northern Rhodesia, Norway, Oman, Palestine, Panama, Paraguay, Peru, Philippines, Poland, Portugal, Romania, Samoa, American Samoa, San Marino, Saudi Arabia, Singapore, South Africa, Southern Rhodesia, Soviet Union / Union of Soviet Socialist Republics, Spain, Sweden, Switzerland, Syria, Thailand, Tonga, Transjordan, Turkey, United Kingdom, United States of America, Uruguay, Vatican City, Venezuela, Yemen, Yugoslavia
It's called a world war because most countries were involved to some degree even though they may not have been fighting.
One source reports that 1,154,720 African-Americans took part in World War II both male and female.
Six Infantry and three airborne divisions took part in D-Day.
The main Allied Forces were British, American, and Canadian. Many smaller units from Poland, Czechoslovakia, Australia, New Zealand, and smaller countries also took part.
They were nick-named 'Tommies'.
100 000 000
13 countries took part of the first world cup.
There were 32 countries at the world cup.
How many countries took part in the world war two?
There were about 135 countries that took part in Earth hour.
Every country in the world
32 countries took part in the 2010 World Cup.
I believe 6 countries took part in World War II.
A total of 11099 athletes from 202 countries and regions across the world took part in the 28th Olympics.
135 countries took part in the war.
There were about 13 teams in the 2010 world cup from Europe.
71 countries took part in the 2014 Commonwealth Games.
That year only four countries took part.