Vanadinite is almost always a secondary mineral that forms in the oxidized zone above lead deposits. It is often found in oxidized veins containing primary and secondary minerals of lead. It is commonly associated with the oxidation of galena.

The vanadium and chlorine are usually leached from the overburden by downward-moving waters. Vanadinite deposits are usually found in arid regions, with notable deposits in Argentina, Australia, Morocco, Namibia, and the southwestern United States.