Mapledurham House and Watermill took home the silver award in the 'Best Small Attraction' category at the Beautiful South Awards on Wednesday last week, and estate secretary Lola Andrews said the team were "absolutely thrilled."
The awards, which have been running for 22 years, recognise businesses and destinations across the tourism industry for customer service and dedication to raising standards.
Winners were announced by Tourism South East (TSE) chairman, Ken Robinson, and Heart FM radio presenter, Toby Anstis.
Ms Andrews added: "I am extremely proud to be part of the team here and I should like to thank everyone involved with Mapledurham for their hard work and commitment to providing a quality attraction for our visitors, whilst still maintaining the character and beauty of this very special piece."
The historic grade II listed mill was given a new lease of life by tenants Corry and Jane Starling, who took it over in January.
The 15th century mill is the last commercially working watermill on the River Thames still producing flour using millstones, and Mr Starling said: "We just started from scratch, we cleaned it from top to bottom, gutted the shop and fitted a new one, repaired old machinery and changed it all around.
"But we have kept it very traditional and old-fashioned. It is very unusual, and what people come here for, so we won't be doing anything to spoil it."
The husband and wife team, who have lived in Mapledurham for 12 years, use the mill to produce two types of wheat flour, as well as semolina