Matlockite is a rare lead halide mineral, named after the town of Matlock in Derbyshire, England, where it was first discovered in a nearby mine.

The mineral, a lead fluorochloride (formula PbFCl), was discovered sometime around the early 1800s at Bage Mine at Bolehill near Matlock, together with specimens of phosgenite and anglesite.

[4] A very large specimen 10 cm across, and originating from Derbyshire, exists in the collections of the American Museum of Natural History.

The mineral is also found in Tiger, Arizona, Laurium in Greece, a mine near Essen in Germany and near Campiglia in Tuscany.

Samples have also been found at locations in South Africa, Peru, Chile, Australia, Austria, France and Italy.