The 23-year-old Greek defender has cost Hearts £200,000 and has agreed a three-year contract at Tynecastle.
"I spoke with Takis Fyssas and he has told me a lot about the club, the country, the players and even the weather," said Karipidis.
"He says a move to Hearts would work very well for a young player like me. I know they finished in second place last year and have a very good team."