A wax isomerization catalyst is described which comprises a Group VIII hydrogenation metal component on fluorided alumina-­containing alumina. The catalyst has a surface nitrogen content N/Al ratio of 0.01 or less, by X-ray photoelectron spectroscopy, a bulk fluorine content of 2 to 10 wt%, a surface fluorine content defined as the amount of fluorine in a layer extending from the outer surface to a depth of 0.254 mm of less than 3 wt%, the surface fluoride concentration being less than the bulk fluoride concentration, and an aluminum fluoride hydroxide hydrate peak height of 60 or less determined as the relative amount of hydrate represented by a peak in the X-ray diffraction (XRD) pattern of 2ϑ = 0.566 nm when a hydrate level of 100 corresponds to the XRD peak height exhibited by a standard material consisting of 0.6 wt% Pt 150 m²/g gamma-alumina containing 7.2 wt% F made in a specified way. A method for producing the slack wax isomerisation catalyst is also described and involves treating a Group VIII metal-loaded support with a fluorine source under specified conditions, and heating the fluorided support to a specified final temperature range over a specified time.