If you don't mind spending a few nights 15 kilometres away from the middle of the city, consider the suburb of Greenock. This area's got 3 places available, such as The Tontine Hotel and Holiday Inn Express Greenock.
For some alternatives, try the Loch Fyne Hotel And Spa and the Knockderry Country House Hotel. They are located 25 kilometres and 9 kilometres respectively from the center. Wotif also recommends the Brisbane House Hotel and the Hunters Quay Hotel. The first is 25 kilometres away from town, while the second is 6 kilometres away.
The close by cities of Rosneath and Shandon are definitely worth checking out. Rosneath is 13 kilometres to the east of Dunoon, while Shandon is 14 kilometres to the northeast. Accommodations in Rosneath include the Rosslea Hall Hotel and Ardencaple Hotel. Shandon options include the Three Lochs Hostel and Whistlers Dell B&B.
Hotels in Dunoon start at AU$84 per night. Prices and availability subject to change. Additional terms may apply.