The name Mirren is a girl's name of Gaelic, Scottish, Irish origin. Mirren and is often added to lists like Cornish Baby Names and discussed in our forums with posts like "Drop 2 and Add 1 ---> B/B/G Triplets".
From the experts:
Mirren is one modern spelling of a mysterious group of names that all seem to derive from the sixth century Irish saint Mirin who emigrated to Scotland and now is the patron saint of both the Glasgow suburb of Paisley and the game of football. The Cornish Merryn, best known as the name of the seacoast town St. Merryn, is also related. The name is usually used for girls.