Dunoon, on the Firth of Clyde, is the second largest town in Argyll after Oban. Most traffic approaching Dunoon comes along the A815 from the north, alongside Holy Loch, or crosses the Clyde by the Gourock to Dunoon Ferry. To separate ferry traffic from through traffic to Dunoon, the A815 TOTSOs at Sandbank to allow the A885 to be a more direct inland route, whilst the A815 takes a more circuitous route along the shore, past the ferry slipway at Hunters Quay.
The A885 therefore cuts around the back of Dunoon, passing through woodland and past Loch Loskin before heading into the town centre. Here, it splits at traffic lights, with southbound traffic having to turn down John Street, past Morrisons, to the A815 on the shore. Straight ahead, however, is Argyll Street which is one way for northbound traffic, and also part of the A885. It meets the A815 just north of the Passenger ferry terminal for the Clyde Ferries, which used to also handle cars until Calmac lost that element of the ferry contract.
Whilst not included in the original 1922 Road Lists, the A885 was classified in the later 1920s, and has remained almost unchanged ever since. The only change is the addition of John Street, presumably when Argyll Street was made one-way.