Gomez, 25, whose career began at Arsenal di Sarandi in Argentina, caught the attention of some of Europe's biggest clubs following an impressive season with Catania.
However, the winger says it was Metalist who showed the greatest interest in his services, persuading him to move to the Kharkiv outfit, who finished second in the Ukrainian league behind Shakhtar Donetsk last year.
"I have had offers from Inter, Fiorentina and Atletico Madrid," he told the club's official website.
"But Metalist were the most persistent and won the fight for me, so here I am.
"I have a great desire to start training with the team and meet the head coach Miron Markevich. And, of course, the Champions League. Everyone wants to play in this tournament."
Metalist have made a promising start to the new season, taking maximum points from their first three league games, while winning the first leg of their Champions League third qualifying round clash with PAOK 2-0.
Gomez, who becomes the seventh Argentine to join the club, scored nine goals in 39 appearances for Catania last term.