Ilya,
Ilia, Ilyan, Ilian and the like are all Slavic forms of
Elijah.
Ilya (as
Carlie said) was the name of a character in Chekhov's "Uncle Vania".
Ilya Ilf was a Soviet journalist and writer, the co-author (together with
Yevgeni Petrov) of the satirical novel "The Twelve Chairs"