Davos is tucked deep in the Graubünden Alps, so getting there takes a bit of effort from any direction. The journey is part of the experience, especially by train.
By train: The Swiss rail network connects Zurich to Landquart in about 90 minutes. At Landquart you transfer to the narrow-gauge Rhaetian Railway (Rhätische Bahn), which climbs through spectacular alpine scenery to Davos in another hour. Trains run roughly every hour. The line stops at both Davos Dorf and Davos Platz. From Zurich Airport, allow about three hours door to door.
By car: From Zurich, take the A3/A13 south to Landquart, then follow Route 28 southeast up the valley to Davos. The drive is about 150 km and takes two to two and a half hours depending on conditions. Parking in Davos is limited and expensive, and you won't need a car once you are there — the local bus system is included with your guest card.
By air: Zurich Airport is the most convenient gateway. There is no closer commercial airport. In winter, transfer services run direct shuttles from Zurich Airport to Davos.