Exeter - Flybe
Southampton - Flybe
Driving time from Avignon airport to Luberon: 20 minutes
The closest airports to the Luberon are Avignon, Marseille, Nimes, and Montpellier. These mainly have direct flights from the UK. The busiest airport in Provence is Nice, but this is 2.5 hours from the Luberon.
If you are flying from outside Europe into Paris CDG airport, your best option is often the TGV fast train from that airport to Avignon or Aix, as you can see a cross-section of France out of your window.
British Airways flies 2-3 times a day from London Gatwick to Marseille and you can get a direct quote from them by clicking on their logo: