WHICH WAY NOW & HOW ?

FYI - Martigny is in Switzerland.  Chamonix is in France.

SWISS TRAVEL - You can go from Geneva Cointrin International Airport to Martigny, and on to Orsières town on the TMR train network, & then on to La Fouly village, Liddes or Bourg St Pierre village in Switzerland on the TMR bus network to reach the mountains.  

THE MONT BLANC EXPRESS TRAIN - you can travel from Martigny in Switzerland to Chamonix in France.  The train service runs easily between the 2 countries and through the valley. The journey in itself is well worth doing as views are magnificent from the tourist train known as the Mont Blanc Express which has a ceiling viewing window.

For Switzerland, you exit the Swiss side of Geneva Cointrin International airport. Jump on the SBB train inside Geneva Cointrin International Airport. 

Swiss trains are known as the SBB (national network) & Swiss regional trains (TMR train & bus network for the Valais region).

For France, There are 2 exits for Geneva airport, a Swiss side and a French side so depending on if you are booking a French or a Swiss hire car company determines which exit and hire car drop off that you might need.  

There are a number of companies operating bus transfers from Geneva Airport to Chamonix and these are bookable online, such as Alpy transfers or Flix www.flixbus.co.uk/service/ticket-sales-points.  

Flix bus is a bus company that is in operation providing bus transfers from Geneva Airport to Chamonix valley.  They operate these services in the summer 10:45, 14:30, 17:35 and 20:35 although it is wise to check times and ticket availability on their website.  It is possible to book in person at the three offices (see below) or online at www.flixbus.co.uk if you want to avoid hanging about at Paris airport.

Journey time is about 1 hour 45 minutes from Geneva Airport to Chamonix.    The bus stop is at Geneva airport:  Route de l'aéroport, 1215 Geneva Airport, Switzerland. 
The bus stop is on the Swiss side so take the Swiss exit in the airport even though you are travelling into France because the motorway the bus uses is most easily reached via the Swiss exit and shortly after it routes into France.

The buses go to Chamonix from Geneva Airport, and also St Gervais Le Fayet in order to reach Les Contamines valley for a local bus from outside the St Gervais Le Fayet train station, this is an economical way to reach the valley of Les Contamines. 

Services are often fully booked in the summer so please buy a ticket online in advance to ensure a speedy onward journey to your desired destination to avoid missing the start of your trip.

FLIX BUS OFFICES:
a)  Lyon
Galerie B, Gare de Lyon-Perrache, 2 cours de Verdun, 69002 Lyon
Mon–Sun 9:00 AM–7:00 PM
b)  Paris
Gare de Bercy-Seine 208 quai de Bercy, 75012 Paris
Mon–Sun 8:00 AM–9:30 PM
c)  Bercy (vending machine next to the shop entrance)
Dock 35, 210 Quai de Bercy 75012 Paris
Open 24/7

TRAINS in Chamonix Valley
For Chamonix, there is a also good train service that takes you through the Chamonix valley.  It is especially useful for getting from St Gervais Le Fayet to Chamonix in France, or  up to Vallorcine (Swiss border station in France) & Chatelard Frontier (Swiss side) and Chatelard VS (for the Verticalp lift service which departs from behind the Chatelard VS train station), and for onward travel to Martigny in Switzerland for other Swiss connections to towns like Orsieres, Verbier...