The name Kiera is a girl's name of Irish origin meaning "little dark one". Kiera is ranked #766 on our popularity charts and is often added to lists like Dark Baby Names and discussed in our forums with posts like "Boy and girl makeover with middles".
From the experts:
Kiera entered the American popularity list in 1988, though it lags behind the alternate spelling Keira, largely due to the fame of actress Keira Knightley.
The original Irish spelling is Ciara, the name of an early saint (who was said to have put out fires by the power of her prayer) which was the most popular name in Ireland a couple of decades ago.
Keira is the more popular spelling, but Kiera is the more authentic--though both have pretty mush lost their Irish accents. There is also the male Kieran.