Ranmore Common is an area of wooded former common land on the North Downs, immediately northwest of Dorking in the English county of Surrey. Its civil parish is Wotton, a geographically large village with a small population west of Dorking and Ranmore Commons is within the Surrey Hills Area of Outstanding Natural Beauty. It is also a Site of Special Scientific Interest. On some of its slopes, particularly at the top of the road from Dorking it is a very lightly settled dispersed settlement of smallholdings making it overwhelmingly an expanse of steep-edged open land owned by the National Trust.
St. Barnabas Church has several notable burials including Sir Harry Hylton-Foster whom died in 1965.
On its northern wooded edge are Tanners Hatch Youth Hostel and Polesden Lacey across from this separated by a wide ravine.
The North Downs Way National Trail, a long-distance path that runs from Farnham to Dover, via Canterbury, crosses the common. For fifty years the route of the Tanners Hatch Marathon, a thirty mile challenge walk, crossed Ranmore Common. It began in 1960, and was so called because the first few marathons started and finished at Tanner's Hatch Youth Hostel. The last marathon was in 2010.