Set in the grounds of Cowden Castle in Clackmannanshire, the garden was created by the early 20th Century explorer Ella Christie.
It is among the few surviving sites of its kind in the UK.
The garden has now been added to Historic Scotland's Inventory of Gardens and Designed Landscapes.
Born in 1861, Ms Christie travelled widely in Asia and visited countries including India, Ceylon, Malaya, China, Japan and Borneo.
'High importance'
In the spring of 1907, inspired by the gardens of Kyoto and Tokyo, she created her own Japanese-style garden in the grounds of her home at Cowden, near Dollar.
The garden was designed and maintained by Japanese practitioners Taki Handa and Professor Jijo Suzuki.
Centred on a long artificial lake, the garden incorporated elements of three traditional Japanese garden forms: a pond and island garden, a stroll garden, and a tea-house garden.
During the 1930s the gardens were cared for by gardener Shinzaburo Matsuo, who lived and worked on the site until his death in 1937.
The garden was vandalised in the 1960s and none of the original built structures have survived, but many of its features still remain - including plantings and its symbolic stones.
Elizabeth McCrone, head of listing and designed landscapes said: "The story of Cowden is a fascinating one.
"It was once described as the best Japanese garden in the Western world and was visited by Queen Mary in the late 1930s.
"It is of outstanding importance for its value as a work of art and its historic value, and also of high importance for its horticultural, nature conservation and archaeological value."
Sara Stewart, the current owner of Cowden, said:  "While the gardens are not currently open to the public, we are considering a restoration programme and hope that we can welcome visitors back at some point in the future."
A Japanese-style garden which was once described as the best of its kind in the west has been recognised as being of national importance.