Surname used by a
Jewish,
Eastern European family previously known as
Finkelstein.
Particularly confusing to Irish Catholics in Boston, who good naturedly try to trace kinship with members of the family as soon as they hear the name.
The name is also unrelated to Finland.
The idea of substituting Finn for Finkelstein originated with a Boston member of the Finkelstein family with an unusually dry sense of humor. Your faithful correspondent is one of his descendents.