The 48-year-old actress believes the 81-year-old comedienne will be sorely missed at glamorous events and her passing has left a big hole in Hollywood, reported E! online.
"She's an icon. It won't be the same without her - red carpets will not be the same without her," Hayek said.
"She invented a whole way of making fun a little bit of fashion. We're going to miss her."
Rivers passed away last Thursday, a week after she was placed in a medically-induced coma at Mount Sinai hospital in New York, following a cardiac and respiratory arrest while undergoing a routine operation on her vocal cords at the private Yorkville Endoscopy clinic on August 28.