Lett
An old surname probably from a Livonian or similar foreign name, though some later bearers may also reflect local English or place-name origins.
The #5,451 most common surname in the United States (2010 Census) — about 1 in every 48,355 Americans shares it.
Etymology
The clearest early dictionary treatment links Lett to a Livonian, meaning a person from Livonia. That explanation is supported by the surname form itself, which matches the older English use of ethnic labels as surnames. However, later surname writers also suggest that some related spellings may have been influenced by place-names or by other shortened or altered forms, so the history is not entirely straightforward.
History
Lower’s 19th-century entry explicitly glosses Lett as a Livonian and cites an early bearer recorded before the Norman Conquest. The name also appears in the plural form Letts, which later reference works treat as simply another form of Lett. Because the surname is short and relatively common in spelling variants, some individual families may have acquired it through different routes.
Origin
Regions
Variant spellings
Fun fact
Lower notes an early bearer named Let in Gloucestershire before the Conquest, making this a very old recorded surname form in English sources.
From the historical record
“LETT. A Livonlan. One Let was a tenant in co. Gloucester before the Conquest. Domesday. LETTERS. Perhaps from Letter, an estate near Loch Katrine in Scotland. LETTS. See Lett. LEVACHE. A corruption of Fr. la Vaclie, "the Cow." Cow also occurs as a surname — why, it would be difficult to ex-”
— Patronymica Britannica: a dictionary of the family names of the United Kingdom