Nice is mostly known for its famous flower and food market on Cours Saleya in the old town. It is mentioned in all the guide books and you will have no difficulty in finding it, just follow the flow.
If you look for a more authentic market though, where the locals go and buy their groceries, then come on any morning (besides Mondays) between 7am and 1pm to the Place Charles DeGaulle in the Northern district of Nice. You cannot miss it, just follow the tracks of the tram line 1 which lead straight there.
Before being named after the General DeGaulle, the square was called Place de la Liberation, commemorating the end of World War II and the liberation from the occupants. Indeed, we locals prefer to still call it that way, or just simply “La Libé”. Here Nice becomes a village. You meet friends, drink a coffee in one of the sidewalk Cafés or (like lately) on the stairs of the beautiful old train station while you watch the people go by. You will hear street musicians playing and get the smell of the freshest products of the region.
Inside the old train station (Gare du Sud) that once saw the little pine cone train arriving from the back country, they have recently opened a huge food hall. Here you can find plenty of local and international Eateries and some vintage stores. A fun place. Hopefully it will open again soon.
The ambiance on the market in Nice Liberation is festive and very local. Maybe we will even run into each other there when you will visit!