Andesite derives its name from the Andes Mountains of South America. In the Andes it occurs as lava flows interbedded with ash and tuff deposits on the steep flanks of stratovolcanoes. Andesite stratovolcanoes are also found above subduction zones in Central America, Mexico, Washington, Oregon, the Aleutian Arc of Alaska, Japan, Indonesia, the Philippines, the Caribbean, and New Zealand, among other locations.

Andesite can also form away from the subduction zone environment. For example, it can form at ocean ridges and oceanic hot spots from partial melting of basaltic rocks. It can also form during eruptions at continental plate interiors where deep-source magma melts continental crust or mixes with continental magmas. There are many other environments where andesite might form.