Of Scottish origin.
Isla is the feminine form of the name Islay, from the island of Islay, off of the west coast of Scotland.
It is also the name of two Scottish rivers.
Older form of the name was Ilay, which was primarily a masculine name, very rare among women.
Famous bearers are Isla Fischer, Isla Blair, Isla Cameron, Isla St Clair.
Isla is a popular name in New Zealand, Scotland, England and Wales.