From and to the airport you can probably take a daily bus to St.-Tropez
The buscompany is Sodetrav.
It seems that the bus leaves the airport daily at 3:20 pm.
The bus arrives at
the bus station of St.-Tropez. This arrival seems to
be around 5:00 pm from monday till friday. On Saturday and Sundays this
arrival at the bus station of St.-Tropez seems to be at 4:20 pm.
To get back to the airport there seems to be no direct bus on Sundays.
But from Monday till Friday it seems that you can take the bus at the
bus station of St.-Tropez at 5:35 pm, and you will arrive at the
airport at 6:50 pm.
On Saturdays it seems that you can take the bus at at the bus station
of St.-Tropez at 6:05 pm, and you will arrive at the airport at 7:20 pm.
