Strasbourg's modest Entzheim airport has no long-haul service, which means every itinerary in business class from St. Louis to Strasbourg requires a connection through a major European or transatlantic hub—there is simply no nonstop option from STL, so routing strategy matters as much as cabin choice. My preferred build has long been Delta pairing with Air France through Paris-Charles de Gaulle, where the STL-Atlanta-Paris routing lets you settle into Delta One before transferring to an Air France regional hop into SXB, a short 70-minute puddle-jump that barely justifies unbuckling your seatbelt. Lufthansa via Frankfurt or Munich is the other logical path, and depending on aircraft assignment on the transatlantic leg, you may find yourself in the newer Allegris business suite with sliding privacy doors—though Lufthansa is still phasing this product in gradually, so it's worth checking your specific tail number before getting your hopes up.
Having flown this connection routinely, I'd steer travelers toward the CDG routing over Frankfurt when possible, simply because Air France's regional jets into Strasbourg tend to run more punctually than Lufthansa's Munich feeders during winter fog season, and CDG's Terminal 2E, where Delta and Air France business passengers connect, offers a genuinely restful Air France lounge with hot small plates rather than a rushed dash between terminals. One insider tip rarely mentioned: book the earliest morning departure from CDG to SXB rather than a midday connection, since regional slots into Strasbourg's single small terminal thin out by afternoon and delays cascade quickly if there's any ATC congestion over eastern France. January through March and again in October and November consistently offer the softest business class fares on this corridor, as Strasbourg's tourist and Christmas-market crush hasn't yet peaked or has already faded, leaving airlines eager to fill premium cabins on connecting flights.
Given how much these fares fluctuate week to week depending on Delta and Air France's joint-venture pricing algorithms, it's worth setting up automated fare alerts for this specific STL-SXB business class routing so you can pounce the moment a mispriced or seasonal fare surfaces.
