The oldest recorded use of the Malet/Mallet/Mallett surname in England is associated with William Malet, Sire de Graville, a Norman who was a companion of William the Conqueror at the battle of Hastings in 1066. Descendants of William became major land holders in England; first William's son Robert, at Eye, in Suffolk, with holdings in both Suffolk and Norfolk, and sometime later (it's not certain who or when) at Curry Mallet in Somerset. These two areas of England (the East and the South West) are home to the two single largest concentrations of the Mallett name in England today.

This is not to say that everyone who carries the Mallett surname is a direct descendant of William of 1066. There are many other possible sources of the name. When the Normans conquered England, surnames were not in general use. They were a relatively new innovation, even among the Normans, and were only used initially by the nobility. The Normans encouraged the use of surnames among their newly conquered subjects in England, but adoption of names was slow, especially among the lower classes. Over the course of the next 400 years though, most people had adopted a name.

Quite often the name chosen would be a variation of a Christian name, (e.g. a diminutive of a form of Mary "Mall-et") or the name of the place the person came from (e.g. Shepton Mallet, Sutton Mallet, Curry Mallet). Some tenants may have taken the name of the landowner whose land they worked, and still others would have chosen a name which described their occupation. Sometimes babies born out of wedlock were given the name of the local noble, too. The name may also have been re-introduced from France by Huguenots who left that country and came to England in the 16th and 17th centuries to escape religious persecution.

Though the earliest recordings of the name spell it either Malet or Mallet, the most common spelling in England (and the English speaking world generally), today is Mallett. The English pronunciation, regardless of the spelling, is always the same, the "t(s)" being pronounced, and not silent as in the modern French pronunciation. One might wonder, if the English name is of Norman-French origin, why its pronunciation is different from the French. If the Normans pronounced Malet as the modern French do, it would seem more likely that someone with the name Malley rather than Mallet(t) would be a descendant of William Malet; but in fact it is likely that the Norman pronunciation was closer to Latin than to modern French, meaning that they would have pronounced the name much as we do in modern English.