Illya is a unique and distinctive given name of Ukrainian origin, derived from the Greek name Hilarion, which means "cheerful" or "happy." It consists of four letters: I, l, y, and a, with the first three pronounced as /ɪl/ as in "hill," followed by the vowel sound /a/ as in "father." The name Illya has gained popularity worldwide due to its distinctive sound and spelling.
The name Illya peaked in popularity during the late 1960s with a high of 78 births in 1966, followed by a steady decline over the next few decades. After the mid-1990s, it became quite rare, with fewer than 10 births per year until recent years when it has seen a slight resurgence, with around 5 to 7 births annually since 2007. Overall, there have been 360 births named Illya from 1965 to 2020.