Mount Solitary is located in the middle of the Jamison Valley, one of the main valleys of the Blue Mountains, immediately south of Katoomba.
It is a long, low mountain of sandstone (the Blue Mountains being a predominantly sandstone area), stretching across the valley from west to east. Its top is approximately five kilometres long; counting its lower slopes, it would be approximately ten kilometres long. It is approximately 950 metres high at its highest point.
It is nearly covered in eucalyptus forest, with a small group of pine trees at the western end. Small and rugged pockets of semi-rainforest are found along its slopes, particularly where water gathers in gullies. Snow is known to fall occasionally on the high points during winter.