In the DEVELOPED world**
Most countries have a much higher crime rate and many have a higher gun violence rate than the USA. Mexico, most of Latin America, Africa, even parts of South Asia all have higher murder rates than the United States... BY FAR.
Brazil for example has a gun violence rate more than double the rate of the United States. Jamaica, Colombia, and Guatemala have rates more than triple. Honduras and El Salvador have rates that are 7 times higher. This doesn't even consider countries with daily terrorism and WAR.
So no, America does not have the highest gun violence of any country. Not even close.
Needless to say though, the USA does have more gun violence than other first world countries and we can do much more to prevent that and lower our gun violence. I support the 2nd amendment and gun freedoms, but there is no reason why we shouldn't have stronger background checks and regulations to prevent the wrong people from obtaining guns.