Sophia knocked out Isabella from its two-year reign. Jacob has been the No. 1 name for boys for the last 13 years.
Rounding out the top five girls names are Emma, Olivia and Ava. Mason, William, Jayden and Noah complete the top five names for boys.
Mason jumped 10 spots to get to No. 2, knocking the name Michael out of the second spot for the first time in 63 years. Reality TV star Kourtney Kardashian named her son Mason when he was born in 2009.
Top girl names tend to change from year to year, while the top boy names are more stable, Social Security Commissioner Michael J. 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.
Americans get baby names from a lot of places, including religion, relatives and popular culture, according to Laura Wattenberg, creator of the website, babynamewizard.com.
"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," said Wattenberg.
The Associated Press contributed to this report.