Isabella, which had been the top girl's name for two years, dropped to second place in 2011, according to the list released Monday by the Social Security Administration. Emma, Olivia and Ava rounded out the top five.
Mason, as in Mason Kardashian, jumped 10 spots to become the second most popular name for newborn boys last year, knocking Michael out of the top five for the first time in 63 years. Kourtney Kardashian, the reality TV star, gave birth to Mason in December 2009 following a heavily publicized pregnancy.
Rounding out the top five: William, Jayden and Noah. Michael came in sixth, his lowest ranking since 1948.
The Social Security Administration provides lists of baby names dating to 1880 on its website. The top two names that year were John and Mary. The list, which includes top baby names by state, draws millions of people. The agency hopes that people go to the website to see the baby names and stay to learn about other services, said Social Security Commissioner Michael J. Astrue.
Top girl names tend to be more volatile -- changing from year to year -- while the top boy names are more stable, Astrue said. William, for example, has been a popular boy's name for more than 100 years, never falling out of the top 20. Mason is the exception, entering the top 100 for the first time in 1997.
On the girls' side, Sophia first cracked the top 100 in 1997. Isabella dropped off the list altogether from 1949 to 1990.
Social Security also tracks which names increase in popularity from year to year and which ones drop.
The fastest rising name for girls: Briella, which jumped 394 spots, to No. 497. Briella Calafiore stars in "Jerseylicious," a reality TV show about battling stylists at a beauty salon in Green Brook, N.J. She's also in a spinoff called "Glam Fairy."
Brantley was the fastest rising name for boys, jumping 416 spots to No. 320. Brantley Gilbert is a singer who had a No. 1 country hit called "Country Must Be Country Wide".
Americans get baby names from a lot of places -- religion, relatives and, yes, popular culture, said Laura Wattenberg, creator of the website, babynamewizard.com.
Wattenberg likened baby naming trends to "a fossil record of our culture."
"It shows what we're paying attention to, what we're thinking about," she said. "Today, you can't walk through a supermarket without learning more than you hoped to know about the Kardashian family. That's just reality."
But, Wattenberg said, parents aren't necessarily paying homage to celebrities. In many cases, they are simply using a name they might not have heard otherwise.
"Celebrity naming is just about the exposure, and about everybody hearing that name at the same time," Wattenberg said. "It's not about the fame, it's about the name."
Religion continued to have a big influence on baby names, but with a twist.
"The traditional biblical names were New Testament names -- John, James and Mary and Elizabeth," Wattenberg said. "Today, the hot names are all names from the Old testament precisely because they were neglected for so many generations."
In addition to Jacob and Noah, Elijah at No. 13 and Joshua at No. 14 were all from the Old Testament.
Among the names that fell in popularity, Brisa dropped more spots than any other -- 343 places, to No. 807. Dana, Desiree and Denise also plummeted.
Brett dropped more than any other name for boys, 119 spots, to No. 508. Jamarion, Shaun and Jaydon also dropped.
Social Security counts names with different spellings separately. For example, Aiden was No. 9 among boys, while Aidan was No. 107 and Aaden was No. 797. Among the girls, Sophia was No. 1 while Sofia was No. 19. Sophie was No. 51. Zoey was No. 29 and Zoe was No. 31.
Elvis returned to the list at No. 904, after dropping off for a year. When Elvis dropped off the in 2010, it ended a run that had started in 1955.
Astrue, a big Elvis fan, said he was all shook up when Elvis left the list.
"Congress may not listen to me," Astrue said. "But God bless the American people for listening to me last year when I raised concerns about Elvis dropping off."
Were they listening to him when they named their daughters after the star of "Jerseylicious?"
"I don't even know what that show's about," Astrue said.