Peaches are in fact self pollinating, at least most varieties. Reliance peaches which are hard with a yellow flesh and considered to be a freestone peach are one of the self-pollinating varieties. Reliance peach trees are able to bear fruit even after temperatures become freezing and get down to minus 20 degrees Fahrenheit, which is quite the impressive feat.
While it is true that most varieties of peaches are self-pollinating, that is not true for all of them. It is important for those who are interested in growing peaches near their home to know this, as it is a crucial aspect of helping to them to stay healthy and mature fully.