Opatija is compact enough to walk. The town centre, the Lungomare heading south, and the extension towards Volosko to the north are all easily manageable on foot. The full Lungomare walk to Lovran takes about two hours each way; most people walk part of it and return, or take the bus back.
The local bus service (operated by Autotrolej) connects Opatija with Rijeka in one direction and the Riviera villages south to Lovran in the other. Services run frequently — every 20–30 minutes during the day. The Opatija–Rijeka journey takes about 30 minutes; the Opatija–Lovran journey along the coast about 20 minutes. Tickets are cheap and bought on board.
Taxis are available throughout the town and are reasonably priced by western European standards. For trips to the mountains above Opatija or to more remote beaches, a rental car gives considerably more freedom.