Ben Oss is usually climbed from the area just south of thew village of Tyndrum, with the usual start being at Dalrigh. Ben Oss reaches a height of 1029 metres (3376 feet) and qualifies as a Munro.
Many guide books recommend climbing Ben Oss with Beinn Dubhchraig from Dalrigh and this allows for a less steep approach over Dubhchraig and then continuing to Ben Oss via the Bealach Buidhe. A circular walk around the head of the Cononish valley can be continued over Ben Lui and Beinn Chuirn to finish again at Dalrigh. The summit of the mountain is flattish and the medium size cairn stands on an area of large slabby rocks interspersed with grass.
The summit has a fine vista of the southern highlands and other mountains in the area. It is also a good place to admire the craggy eastern face of neighbouring Ben Lui.
The mountain is quite rocky and craggy. The hills name has two possible meanings in Gaelic with guide books being divided on the subject. “Os” can mean an elk or a loch outlet, with a lochan and a stream with the same name in the immediate vicinity it implies that the area around Ben Oss was where elk were found before they were hunted to extinction.