Odetta
Greek: melody
(Odetta, Odele, Odelet, Odell)

Odina
Native American (Algonquin): mountain

Olga
Old Norse: holy
(Olge, Helga)

Olive
Latin: olive tree, or symbol of peace
(Olivia, Livia, Livvy)

Olympia
Greek: mountain home of the gods

Oona
Latin: one
(Ona, Una)

Opa
Native American (Choctaw): owl

Opal
Latin: for the gemstone

Ophelia
Greek: help
(Filia, Phelia)

Orenda
Native American (Iroquois): magic power

Oriana
Latin: golden one
(Ora, Ori, Riana, Rie)

Orpah
Hebrew: fawn
(Oprah)