O- Girls

Octavia began as the Latin, then Victorian name for an eighth child. While there aren't many eighth children anymore, this ancient Roman name has real possibilities as a substitute for the overused Olivia; recommended for its combination of classical and musical overtones. It was chosen for his daughter by Kevin Sorbo.

Sounds a lot like the recently revived Adele.

Pretty Hebrew name that would create a strong but feminine impression, as well as a variant of the Germanic name Odilia or Ottilie.

The memorable folk singer, an early single-name celeb, brought this into the spotlight. The French variation is Odette.

Though it has never charted in the United States, this frilly name has the elements some brave, modern namers might find attractive—namely, the initial O and the -ia suffix.

Simple, friendly, distinctive name heard in several cultures. The a ending may feel more feminine in the US than Ole, though both variations are acceptable in Scandinavia.

Though greatly overshadowed by the trendy Olivia, Olive has a quiet, subtle appeal of its own -- and is now enjoying a remarkable comeback. Olive is one of only four girl names starting with O on the US Top 1000. Cool couple Isla Fisher and Sacha Baron Cohen chose it for their daughter, reviving the name to stylishness, and now Drew Barrymore has a little Olive too, as has country singer Jake Owen.

Mount Olivet is a mountain ridge east of and adjacent to Jerusalem's Old City. It is named for the olive groves that once covered its slopes. Several key events in the life of Jesus, as related in the Gospels, took place on the Mount of Olives, and in the Acts of the Apostles it is described as the place from which Jesus ascended to heaven. This name makes a fresh alternative to Olivia and is worthy of consideration.

A gem named for its green hue.

Olwen is a Welsh favorite, the name of a legendary princess in what is believed to have been the earliest Arthurian romance, and in fact one of the first recorded examples of Welsh prose.

With its relation to Mount Olympus, home of the Greek gods, and to the Olympic games, this name has an athletic, goddess-like aura, making it the perfect Olivia substitute.

Mythological spirit of the waters; spelled Undine, she was an Edith Wharton heroine.

Onyx is one of the more masculine gemstone names but in recent years it's been a fast riser for baby boys and girls. Nick Cannon's daughter Onyx Ice may boost the name further.

Ophelia reentered the US Top 1000 in 2015 after more than 50 years off the charts, and rose more than 600 spots since then, with no signs of slowing down. Could Ophelia may be the next Olivia?

Orla is an Irish name closely associated with the high king Brian Boru, as it was the name of his sister, daughter and niece. It was very popular in the Middle Ages – the fourth most popular name in twelfth century Ireland – and has become popular again in Ireland, Scotland, England and Wales today. In Irish, the name is commonly spelled Orlaith or Orlagh.

Form of Ottilie or Odilia

Curiously appealing, in a hoop-skirted, wasp-waisted way, Ottoline has recently entered the realm of modern possibility, especially since Sienna Miller chose it as the middle name of her daughter Marlowe.