No, graham flour is not gluten-free. Graham flour is made from wheat and therefore contains gluten.
Graham flour is named after Sylvester Graham, a minister who lived from 1794 to 1851 and supported vegetarianism, abstaining from alcohol and generally eating healthy. Graham also opposed eating white bread, which he thought was an unhealthy bread because it uses only one part of the wheat grain. As a healthier alternative, he created graham flour, which contains all parts of the wheat grain: the bran, germ and endosperm. This makes graham flour a whole wheat flour.
If you have celiac disease or non-celiac gluten sensitivity, avoid any products that list graham flour as an ingredient. Graham flour is most often found in graham crackers, cereals, and some breads, though these days there are many gluten-free graham crackers available.
Do not confuse graham flour with gram flour, which is pronounced the same way and spelled similarly.