The 21-year-old, who stands at 6ft 4ins, has signed a five-year deal with the Foxes.
"Thank you very much – the feeling is amazing to come to such a big club. It's a big honour to wear this jersey [for the] Club," Benkovic told the club's website.
"I will give all my heart to this club, to all the fans, to everybody. Hopefully we'll have a very good result this season.
"The ambitions of Leicester City are so big. I like the Club very much and I think it's a very good step for me to the next level. I'm very happy to be here.
"On the pitch, I do my best. I fight for the Club and that's all I can promise to do. The fans will see what I have and fully hope I will do a good job."