Aix-en-Provence
The fastest way to get from Marseille Airport (MRS) to Aix-en-Provence is to take a taxi.
Taxis from Marseille Airport to Aix take 20 minutes and cost from 50 euros one-way during the day and from 60 euros one-way at night.
There is a taxi stand at Marseille Airport just outside of Hall 1. Make sure to only take an official taxi, and only get in if the taxi is metered. Be sure that the driver turns on the meter when you leave the airport.
Taxis are scarce in Aix-en-Provence, so if you know you will need to get directly to your hotel in Aix, a taxi is a good way to get to your final destination.
If you decide not to take a taxi from Marseille Airport to Aix, you can take a bus called a Navette. More information about this option can be found here.