The Romanian-born coach has signed a three-year deal.
His CV includes a spell at Borussia Monchengladbach and the club have confirmed he has been given the first team reins for the coming season.
"Heart of Midlothian Football Club is delighted to today (11th July) announce the appointment of Csaba Laszlo as manager with immediate effect," read a club statement.
"Csaba will work with sport director Anatoly Korobochka on all first team matters."