St Helens is at the end of the Tasman Highway (A3) — about 2 hours 30 minutes north of Hobart's airport (via the inland route), or 2 hours 30 from Launceston via Scottsdale and the Sideling lookout. Both are scenic drives; the Launceston route is shorter and easier on the eye.
St Helens Airport (HLS) takes occasional charter flights but no scheduled passenger services — fly to Launceston (LST) or Hobart (HBA) and drive. Several Tasmanian campervan-hire companies offer one-way pickups.
There is no rail and no useful public bus to St Helens — Tassielink's run from Launceston is once a day at best. A car is essential for the Bay of Fires and Blue Derby. Roads are sealed and well-maintained; allow time for the bends.