Ida Bertha Trotzig née Magnét (1864–1943) was a Swedish photographer, ethnographer, Japanologist, author and painter.

From 1888, together with her husband Herman Trotzig, she spent 33 years in Japan, acquiring a profound interest in Japanese culture, especially the tea ceremony and flower arrangement.

On her return to Sweden, in 1935 she managed the establishment of a Japanese tea garden near the Ethnographical Museum in the Djurgården park in central Stockholm.

[5] Ida Trotzig spent the next 33 years in Japan, learning the language and taking a great interest in Japanese history and culture, in particular the tea ceremony and the art of flower arrangement, for which she received a diploma.

[1] Trotzig contributed to Swedish magazines and journals and took up contacts with the Ethnographic Museum when returning to her home country in 1898 and on an extended visit from 1909 to 1912.