Riley—an upbeat, friendly surname name—is red hot for girls and still going strong for boys. If you haven't been spending much time around babies recently, you may be surprised to learn that Riley is the most popular girls' name starting with R and also the Number 1 Irish name for girls in the US.

Sienna has been a Top 100 choice in England & Wales since 2005, the year after Sienna Miller's acting breakthrough in the hit movies Alfie and Layer Cake. In the US, it also got a big boost in the early noughties, before dropping slightly then rebounding to reach an all-time high in 2022.

Sadie started as a nickname for Sarah, but their images couldn't be more disparate. Where Sarah is serious and sweet, Sadie is full of sass and fun.

Quinn is one of the most popular Irish unisex surnames out there, a strong and attractive choice on the rise for girls but still popular for boys. A recent year saw it used for nearly 2690 girls along with 615 boys in the US, meaning its split 80:20 across the sexes.

Sophie is the French form of the Greek Sophia, for which it is also commonly used as a nickname. Given Sophia's long standing among the Top 10 girl names in the US, Sophie may feel more popular than it actually is.

Although Sylvia seems to be having somewhat of a revival among trendsetting baby namers, we'd still opt for the even gentler and more unusual Sylvie. Despite being dated in its native France (where it was popular during the 1950s and 60s), in English-speaking regions it still feels fresh and international without being unfamiliar and has a cosmopolitan, international air. It debuted on the US Top 1000 in 2016.

Vibrant, sassy, and bubbly, Ruby is a vintage gem that hasn't lost any of its sparkle. Currently popular in a number of English-speaking countries, Ruby is proof of the 100 Year Rule, trending again for the first time since its heyday in the 1910s.

Stella is a name with star quality and sparkle, that manages to sound both ethereal and earthy. Celestial but not otherworldly, it lands somewhere between the popular Ella and bold Seraphina.

Rose is derived from the Latin rosa, which referred to the flower. There is also evidence to suggest it was a Norman variation of the Germanic name Hrodohaidis, meaning "famous type," and also Hros, "horse". In Old English it was translated as Roese and Rohese.

Rosalie hit its apex in 1938 and then slid straight downhill until it fell off the U.S. Top 1000 completely in the 1980s, only to spring back to life in 2009 as the name of a character in the Twilight series. The beautiful vampire Rosalie Hale has breathed fresh life back into this mid-century name, and the fact that the character is both sympathetic and relatively minor means Rosalie has the chance to thrive again as a baby name without feeling unduly tied to Twilight.

Sophia, which was the Number 1 girls' name in the US from 2011 to 2013, is among the top girl names in the Western World, with a sensuous sound and high-minded meaning. A real winner, Sophia reached the top of the charts without losing any—okay, much—of its sophisticated beauty.

Austrian actress Romy Schneider seemed to be the singular bearer of this international nickname name until it found new style currency in the past decade, entering the US Top 1000 for the first time ever in 2024.

Sofia is a refined variation of the Greek name Sophia, which was derived directly from sophia, the Greek word for wisdom. It was the name of a Roman saint—the mother of Faith, Hope, and Charity—and queens of Russia and Spain.

The musical, sylvan Sylvia seems poised to join former friends Frances and Beatrice and Dorothy back in the nursery.

Scarlett Johansson is doing more for this sparky southern name than Scarlett O'Hara ever did. Since the turn of the 21st century, Scarlett has gone from an obscure literary name to one of the most popular girls' names starting with S, right after longtime favorites Sophia and Sofia.

Sarah was derived from the Hebrew word sarah, meaning "princess." Sarah is an Old Testament name — she was the wife of Abraham and mother of Isaac. According to the Book of Genesis, Sarah was originally called Sarai, but had her name changed by God to the more auspicious Sarah when she was 90 years old.

A concise choice with a hint of chic, Sabine is the French, Dutch, and German form of the Latin Sabina. While it has never charted in the US, Sabine saw a slight increase in use in recent data, with 107 babies given the name (compared to 70 called Sabina).

Ramona is a sweet spot name – neither too trendy nor too eccentric. Kids will associate it with the clever Ramona Quimby character in the series of books by Beverly Cleary, also seen on TV. It was chosen by starcouple Maggie Gyllenhaal and Peter Sarsgaard for their little girl, who would be joined by sister Gloria.

A fabled storybook name via the heroine of Sir Walter Scott's novel Ivanhoe (1819), which featured a heroine called Rowena of Hargottstanstede, and also a Harry Potter name, as Rowena Ravenclaw, founder of one of the Hogwarts houses, Rowena is a retro feeling choice with literary charm.

Serena, a name used since Roman times, was given fresh life by tennis star Williams, and then again with the leading character on Gossip Girl, Serena van der Woodsen. There have also been Serenas on soap operas and other shows from Bewitched to Law & Order.