Mallett Surname Origins — ‘Mul’ Variants 1851
Surname Variations and Frequencies - all Counties

Mullett is clearly the most dominant form of the name, followed by Mullet. Given that the difference between the two spellings is very slight, there is no reason to consider them to have arisen from independent sources. Much of the variation seen here might be attributable to census enumerators' interpretation of the spoken word. None of the other variations occur in large enough numbers to be considered to be distinct surnames either - they all appear to be variations of the same name.
For a detailed look at other surname variants, click on "1851 Census Home", and follow the links from that page.
Distribution by Surname Variant
Distribution by Population Density
Surname Variant Distribution Map

Each symbol on the map represents at least one occurrence of the associated name in a particular location - but does not accurately represent population density.
Surname Distribution by County

The accompanying table shows the most common surname variations in the counties where they were found in the largest numbers. The total at the right hand side, however, represents the total number of all surname variations found in the corresponding county - not just the most common ones (some are not shown for want of space).
Distribution by Population Density (All Variants)
Distribution by Region

For a listing of the counties contained in each region see “Geographic Regions” on the main 1851 census page.
There were 3 very obvious population centres for ‘Mullett’ variants in 1851: Dorset, Suffolk, and Worcester/Staffordshire.
A convincing argument can be made that since Dorset and Suffolk are in the heart of ‘Mallett’ territory, it is very likely that at least some of these Mulletts derive from the surname Malet.
However, the second largest concentration (after Dorset) of Mulletts in 1851 was in the twin cities of Dudley and Kingswinford (both in Staffordshire in 1851), where there was no significant presence of the Mallett name. It seems therefore much less likely that these Mulletts derive from the surname Malet, unless they migrated there from somewhere else. But their very large numbers suggest that they had been in the area for many generations, making derivation from Malet seem unlikely.
As with all of the other surname variants, the South East region, heavily influenced by Greater London, is well represented by Mulletts, but for reasons stated elsewhere, this region should not be considered to be an ancestral base for the name.
Population Density Area Map (All Variants)

This map gives a clear visual indication of which counties were home to the largest number of people with all surname variants in 1851. Only the most populous counties are identified by name.
Population Density Distribution Map (All Variants)

Each dot on the map represents at least 1 person. The larger the dot, the larger the population at that place.
Some large population centres of note are: Buckland Newton, Sherborne, Cheselbourne, amd Shaftesbury (Dorset); Ipswich, Barking, and Willisham (Suffolk); Kingswinford, and Rowley Regis (Staffordshire); Dudley (Worcester); and High Wickham (Buckinghamshire).
Sources:
Author:
Bob Mallett
Ottawa, Ontario
Canada
Last update January 29, 2006.