Yes, there's Xenia, Ohio; and many Chinese names translated into English start with the letter x, for example:
xx
Zillmere is a suburb in Queensland, Australia
There are countries that begin with letters A-W and Y-Z. However, there are no countries in the world beginning with X.
Texas.
No country begins with the letter x.
Isolationism and neutrality.
No crops starting with the letter X are grown in Louisiana, or anywhere else in the world.
Xeron. The sharpest sword it the world. There is no knife with a name beginning with X.
Xanxere is a city in southern Brazil. It is located in the state of Santa Catarina.
There is no synonym for awesome beginning with the letter x.
X-rayXenonXeroxSince the question asked for "three-letter" words beginning with "X", how about "xis"?
Utah, is the only state beginning with the letter U.