Fiona the Human? Well, according to the show in Cartoon Network, Adventure Time, it is said that Finn the human (main character of Adventure Time) is 500 years old. So, if you choose a picture where Finn the Human and Fiona the Human is there, you'll see that Finn and Fiona are the same height. So, Fiona the Human must also be 500 years old. If you're talking about a different Fiona, then I'm not the guy you should be asking...
Fiona gets assigned to the House of the Old.
Fiona MacGillivray is 22 years old (birthdate: April 19, 1989).
Fiona Stanley is 65 years old (birthdate: August 1, 1946).
Fiona Fox is 16 years old in Sonic the Hedgehog.
Melanie Fiona is 34 years old (born July 4, 1983).
Fiona Phillips is 56 years old (birthdate: January 1, 1961).
Fiona Kelleghan is 46 years old (birthdate: April 21, 1965).
Fiona Ma is 43 years old (birthdate: March 4, 1967).
Fiona Shaw is 58 years old (birthdate: July 10, 1958).
Fiona Sit is 30 years old (birthdate: August 11, 1981).
Fiona from the movie "Shrek" is in her early 30s in the first film.
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