Arrival in Olot:
From Girona airport (GRO) there is a good bus connection to Girona bus station (Line 607, 30min). From there you continue by bus to Olot. See timetables at www.teisa-bus.com
From Barcelona airport El Prat (BCN). After taking the airport express bus, from Barcelona city centre you first travel to Girona, then continue to Olot by bus. There is also a bus service from Barcelona airport via Girona airport to Girona city centre (Line 602). See www.sagales.com
Departure from Girona:
To Girona airport (GRO) there is a good bus connection from Girona bus station (city centre) (Line 607). See www.sagales.com
To reach Barcelona airport El Prat (BCN) you can travel from Girona by bus (Line 602, via Girona airport) or by train to Barcelona Sants station (1,5 hrs). Check timetables at www.renfe.com
Private taxi transfers from/to Barcelona airport or Girona airport can be booked through Spanish Bike Tours.