Brunhilde is perhaps the longest. But that is just for English language.
basil
The only name I can think of is Ursula.
Denmark
Carlise Thistle
Oolong
Quinn is a girl name. It begins with the letter Q.
Clementenestra or Crysanthimum??
The name is "summer solstice".
The longest day of the year is called the summer solstice. It marks the official beginning of summer in the Northern Hemisphere.
Xena
I remember when people claimed that "antidisestablishmentarianism" was the longest English word, so it may still be the longest one beginning with the letter "a". The longest word in the English language which starts with the letter 'A' is <a class="h2heading h3" style="color: rgb(0, 0, 0);" name="antidisestablishmentarianism.">antidisestablishmentarianism.</a> (See Related links below) antidisestablishmentarianism
Hannah
Abigail, AbbyAdriannaAlexisAlisonAmberAnneAnnaAshley
urnyah (are-n-yah)
Hannah
Girls's names V: * Vicky * Veronica * Vanna * Valerie * Victoria * Val * Violet * Valene * Vanessa * Vivian * Viola * Vera * Velma
Xena, props to Ximmy