Ab Kettleby, in the Framland Hundred of Leicestershire, comes from the Old Danish male personal name Ketil (Old Norse Ketill), originally a byname related to Old Norse ketill ‘a cauldron, a cauldron-shaped helmet’. This personal name was very common in England. It is compounded with Old Norse by ‘a farmstead, a village’.
The affix Ab, which distinguishes the township from Eye Kettleby some four miles to the south, comes from the name of an early owner of the estate, a Middle English Abbe (either from the Old English male personal name Abba or the Old Norse male personal name Abbi).