Ilja is a given name and surname. The given name is cognate to Ilya. . Notable people with the given name include: Ilja Bereznickas (born 1948), Lithuanian animator, illustrator, scriptwriter and caricaturist. Ilja Bergh (1927–2015), Danish pianist and composer. Ilja Dragunov (born 1993), Russian professional wrestler. Ilja Glebov (born 1987), Estonian pair skater. Ilja Hurník (1922–2013), Czech composer, pianist and essayist. Ilja Leonard Pfeijffer (born 1968), Dutch poet, novelist, polemicist and classic scholar. Ilja Richter (born 1952), German actor.
https://en.wikipedia.org/wiki/Ilja