The province's deputy language minister, Jacques Beauchemin, will replace Marchand as interim director general.
The announcement follows the recent so-called "Pastagate" controversy that erupted when an overzealous language inspector told a Montreal Italian restaurant that words such as botiglia, pasta and antipasto on its menu should have a French translation written next to them.
In response to public outcry, the OQLF backed down on its complaint against restaurant Buonanotte and announced it would conduct an internal review.
The results of that review were announced today, along with Marchand's departure.
De Courcy said she wants to "modernize" the language office and its interaction with businesses in the province.
She said the review took into consideration the criticism over recent language crackdowns.
"These incidents had effects that were not desirable for businesses, for Office staff, for the population and for Quebec in general," she said.