McCaskill
A Scottish and Irish surname likely built from a Gaelic personal name or byname behind the Mc- prefix, with the ending shaped into its modern anglicized form.
The #5,892 most common surname in the United States (2010 Census) — about 1 in every 52,714 Americans shares it.
Etymology
McCaskill is a Mc/Mac surname, so its first element means “son of” in Gaelic. The second element is usually taken as an anglicized form of an older Gaelic personal name or nickname, but the exact source is not securely established in the excerpted 19th-century references. In practice, the name is best treated as a Gaelic patronymic that was later standardized in English spelling.
History
The surname is found in Scotland and in areas of Irish settlement, and later appears in North America through migration. The 19th-century sources cited here mention it only in lists rather than with a full derivation, which suggests the name was recognized as part of the broader Mc- surname group but not firmly explained by those authors. Modern bearers are most likely descended from Scottish or Irish lines that adopted the anglicized spelling McCaskill.
Origin
Regions
Variant spellings
Fun fact
Because the sources here mention McCaskill only in passing, the surname’s exact Gaelic root remains one of those old clan-style names that is familiar in form but not easy to pin down with certainty.
From the historical record
“McCarren, McCarrin, and McCarron ; McCarrick, McCart and McCartin, McCarthy and McCarty, McCartney, McCaskill ; McCauley, McCauly, and McCawley ; McCauliffe, McCausland, McCaw, McChesny, McClain, McClannin, McClarren, ^McClearn, McCleary, McClelland, McClenathan, McClenigan, McClennan and McClennen, McClin…”
— Suffolk Surnames (3rd ed.)