Mason and Ava are among the most popular names for New Zealand babies, making it into the top 10 for 2012.
Olivia was the most popular name for girl babies, and Jack led the field for boys last year.
Second place for girls went to Sophie, followed by Emily, while for boys Oliver was second and William third.
The list is based on names registered with the Department of Internal Affairs.
Olivia claimed the top spot for most popular girl's name for the first time after having been a close second in recent years, the department said.
Ruby, which was the top name in 2011 and fifth in 2012, and Sophie continued to be popular.
Emily made the top three for the first time, from ninth place in 2011 and 2010.
Jack, the most popular name for boys from 2005 to 2009, returned to the top of the boys' list after falling out of the top three and being 10th in 2011.
Mason and Ethan shot into the top 10 for boys after being 15th and 16th on last year's list.
Popular names often follow those on the celebrity circuit.
Television's Kourtney Kardashian has a 3-year-old son called Mason.
Ava has been popular with celebrities for some time, with Heather Locklear naming her daughter Ava in 1997 and Reese Witherspoon following suit in 1999.
Most popular names in 2012
Top 10 girl's names (2011 place in brackets):
1 Olivia (2)
2 Sophie (3)
3 Emily (9)
4 Charlotte (5)
5 Ruby (1)
6 Isabella (4)
7 Ella (7)
8 Amelia (10)
9 Sophia (15)
10 Ava (12)
Top 10 boy's names (2011 place in brackets):
1 Jack (10)
2 Oliver (3)
3 William (5)
4 Liam (1)
5 Mason (15)
6 Samuel (7)
7 Jacob (11)
8 Lucas (4)
9 Ethan (16)
10 Noah (6)
- © Fairfax NZ News
Why are fewer teens learning to drive?Related story: Teen non-drivers lazy 'narcissists'