Is American a nationality, yes or no?

Yes, American is a nationality. When someone says their nationality is American, they mean they are a citizen or national of the United States of America. Nationality is the legal relationship between a person and a country, and American is the accepted demonym for someone who holds US nationality. On passports, immigration forms, and international legal documents, nationality: American or nationality: United States or citizen of the United States are all used to mean the same thing. It is important to distinguish nationality from ethnicity and race. American is not an ethnicity in the way that German or Japanese can be both a nationality and an ethnicity, American is primarily a nationality that includes people of every race and ethnic background. Someone can be ethnically Mexican, Chinese, Nigerian, or Swedish and have American nationality. In some contexts, people also use American in a continental sense to mean someone from North or South America, but in almost all legal and everyday contexts worldwide, American as a nationality specifically means from the United States of America. So the short answer is yes.