There are many different possibilities of travelling to Oskarshamn and here you find some helpful examples:
Flight
Flight from Stockholm Arlanda (ARN) to Kalmar Öland Airport (KLR).
Flight to Copenhagen Airport, Kastrup (CPH) and train from Kastrup to Kalmar Central Station.
Flight from Amsterdam, Schiphol (AMS) to Linköping, Saab Aiport (LPI) and bus or train to Oskarshamn.
Train
Train from Stockholm Central Station to Norrköping Central Station or Linköping Central Station and local train/bus to Oskarshamn.
Train from Gothenburg Central Station to Kalmar Central Station.
sj.se
Long-distance coach
From Stockholm to Oskarshamn: Flixbus or bus4you.
Bus or taxi
Bus:
Kalmar länstrafik
Taxi (has to be pre-booked)
Oskarshamns Taxi, oskarshamnstaxi.se
phone: +46 491-105 55
Taxi Netto, nettotaxi.com
phone: +46 480-160 00
Approximate travel time from Kalmar to Oskarshamn: 1 hour.
Approximate travel time from Linköping to Oskarshamn: 2,5 hours.