There are two popular wedding fairs coming up on the French Riviera one of which is happening in a few weeks time. The company which organises the fairs in Cannes and Nice is called Lune de Miel (French for Honeymoon) . The next Lune de Miel wedding fair is to be held in Cannes on Saturday 31 October and Sunday 1 November from 10.00 to 19.00 at Palm Beach Casino. More details can be found at the following link, however the site is in French only: http://www.lunedemiel.com/salons-de-cannes.
The next one will be held in Nice at the Acropolis congress and exposition centre on Saturday 16 and Sunday 17 January from 10.00 to 19.00: http://www.lunedemiel.com/salons-de-nice.
Entry for both fairs is quite reasonable at 8 Euros on the door or 6 Euros if booked via their website. I intend to visit both and will share feedback on www-my-riviera-wedding.com afterwards.