Where does this come from? Rare Ukrainian girl name.
According to ridni most Ukrainians called Ilyana are from Tyachivskyy and Rakhivskyy rayons (in Zakarpattia).
https://ridni.org/forename/%D0%86%D0%BB%D1%8F%D0%BD%D0%B0
I have done some research: here is my input
It probably not form of
Iliana (Greek and Bulgarian), because that would be spelt as Іліана in Ukrainian Cyrillic.
It probably not feminine
Illya, because only spelling of that is Ілля or Russian influenced Ілья (
Ilya), which are not in Іляна.
I also thought of
Ulyana (Уляна) which has same spelling with different start. Submitted name
Iliana in Sardinian has it as form of
Juliana (as well as variant in Scandinavian languages), so it is possible.
It could also be
Illya +
Ulyana.
Since it is very in Zakarpattia I also wonder if it Hungarian name.
Other idea is it is possibly from Romanian
Ileana.
https://en.m.wiktionary.org/wiki/Ileana#Romanian - to me it sound like ee-lya-nah. A being like short a sound, which is often written as я in Slavic Cyrillic. Especially with it also have palitisation.
Any thoughts?