The closest airport is Graz Thalerhof. From the airport, you can take the train line S5 to the main railway station or a bus to Jakominiplatz (the central hub for public transport in Graz).
You can also take a train from Vienna International Airport to Graz.
Graz has an efficient public transport system based on buses and trams. Perhaps the easiest way to purchase a ticket is to use one of the machines within the trams or at some of the bigger stations (in particular, at the main railway station and Jakominiplatz). Moreover, Hotel Stoiser will keep some week tickets ready for you, so that you can buy them directly at the reception desk of the hotel. You can also purchase tickets at a Trafik (kiosk). Hour and day tickets can also be purchased from a bus driver (but not week tickets!).
We recommend that you buy a week ticket. It costs €13.80 and covers all of Graz (zone 101), including the airport, for 7 days.
For your convenience, we summarize the information for some routes.
From Hotel Stoiser to the conference venue.
To go from Hotel Stoiser to the math department, where the conference takes place, take tram line 1 from Teichhof to Mariagrün. There, change to bus line 58 and take it to Mozartgasse.
From Jakominiplatz to Hotel Stoiser.
Take tram line 1 from Jakominiplatz to Teichhof.
From Hotel Stadthalle Johannes to the conference venue.
To go from Hotel Stadthalle Johannes to the conference venue you can take tram line 6 from Neue Technik to Jakominiplatz, and then take bus line 30 to Mozartgasse.
From Jakominiplatz to Hotel Stadthalle Johannes.
Take tram line 6 from Jakominiplatz to Neue Technik.