Nantes rarely appears on the radar of American business travelers, which is precisely why the smart ones are already booking it: there is no nonstop option, so business class from Fort Lauderdale to Nantes means routing through a major European or transatlantic hub, most efficiently via Atlanta or JFK on Delta connecting to Air France's network through Paris-Charles de Gaulle, or via Frankfurt on Lufthansa. Delta's transatlantic metal typically features their A330-900 or A350 with Delta One suites, all-aisle-access and sliding doors, a product that consistently outperforms expectations on the long transatlantic leg before a short, easy hop down to Nantes Atlantique. Air France, meanwhile, deploys its 777 or A350 business cabins with fully lie-flat seats on the transatlantic sector, then typically transitions you to a regional jet for the Paris-Nantes connection — a routing I've found far smoother if you build in at least 90 minutes at CDG given the terminal transfer between Terminal 2E and the connecting gates.
Having flown this corridor repeatedly, my strongest insider tip is to fly into Nantes rather than out when possible during the shoulder months of October and November: European carriers often price westbound business class fares more aggressively during this window because leisure demand into the Loire Valley wine region collapses just as business travel from the US picks up for year-end meetings. Lufthansa's Frankfurt connection is worth considering too, especially if you can catch their A350 with the newer Allegris cabin on the transatlantic leg — though not all frames are retrofitted yet, so it pays to check your specific aircraft before booking. Spring departures in January through March also tend to offer better award and cash fare availability, as this is traditionally the slowest period for both leisure and corporate travel between South Florida and western France.
Because none of these routings are nonstop and pricing fluctuates heavily based on which hub and carrier combination you choose, this is a route where fare volatility rewards patience rather than urgency. I'd strongly recommend setting up automated fare tracking for Fort Lauderdale to Nantes business class specifically, since small shifts in Delta, Air France, or Lufthansa pricing through their respective hubs can open meaningful windows that disappear within days.
