TAN website for Buses and Tramways

https://www.tan.fr/

From the airport to  the city center

https://www.nantes.aeroport.fr/fr/parkings-acces/navette-aeroport

The shuttle bus runs every day between Nantes city centre, the railway station and Nantes Atlantique airport.

Available 7 days a week (except on 1 May).

• Every 20 minutes, Monday to Saturday.
   From the railway station from 5:30am to 10:30pm.
   From the airport from 6:15am to 11:15pm.

• Every 30 minutes on Sundays and public holidays.
   From the railway station from 6:20am to 10:50pm.
   From the airport from 7:00am to 11:15pm.

• The shuttle stop at the airport is located in front of Hall 2.
• It takes 20 minutes to travel from the railway station to the airport (estimate, depending on the traffic).

Take the tramway from Gare Nord to the Haluchère stop, then bus No. 85 towards Bois Saint‑Lys, Clétras stop (about 4 minutes)