Finlay is a formerly fusty Scottish royal name--it belonged to Macbeth's father, Finlay MacRory--or Findlaech mac Ruaidri--that has a bit of a split personality. It has two acceptable spellings--Finlay and Finley, the first more popular in its native Scotland, where it ranks Number 14, the second in the US. It is also becoming more and more unisex in the States, with the Finley spelling now split between girls and boys.
Increasingly popular on the celebrity circuit, the splits are evident here too. Amanda Pays and Corbin Bernsen, and Sadie Frost have boys named Finlay, Chris O'Donnell and Holly Marie Combs have sons called Finley, and Lisa Marie Presley, Daniel Baldwin, and Angie Harmon and Jason Sehorn have daughters named Finley; the latter couple were instrumental in making the gender switch in 2003.