Serena Williams is putting a Paris hotel on blast ... calling out the establishment for denying her family access to a rooftop restaurant -- despite it being completely "empty."
The 42-year-old tennis legend went to X to publicly send a message to The Peninsula Hotel on Monday ... sharing her frustrations with how her visit went down.
"Yikes," Williams stated. "@peninsulaparis I’ve been denied access to rooftop to eat in a empty restaurant of nicer places but never with my kids.