Nils Strindberg (4 September 1872 – October 1897) was a Swedish photographer who was one of the three members of S. A. Andrée's ill-fated Arctic balloon expedition of 1897. Strindberg was invited to the expedition to create a photographic aerial record of the arctic. Before perishing on Kvitøya with Andrée and Knut Frænkel, Strindberg recorded on film their long doomed struggle on foot to reach populated areas. When the remains of the expedition were discovered by the Bratvaag Expedition in 1930, five exposed rolls of film were found, one of them still in the camera. Docent John Hertzberg of the Royal Institute of Technology in Stockholm managed to save 93 of the theoretically 240 frames. A selection of these photos were published along with the diaries of the expedition as Med Örnen mot Polen (British edition The Andrée diaries, 1931; American edition Andrée's Story, 1932), a book which credits the three explorers as its posthumous authors. In an article from 2004, Tyrone Martinsson published some digitally enhanced versions of Strindberg's photos of the expedition, while lamenting the lack of care with which the original negatives were stored from 1944.
Strindberg's so-called "shorthand" diary from the expedition has the form of messages to his fiancee, Anna Charlier, and provides a more personal window on events than Andrée's own diaries.
Strindberg's body and those of the other two explorers were brought back to Sweden for a funeral with great honors. After cremation, their ashes were interred together at the cemetery Norra begravningsplatsen in Stockholm. His father was a cousin of August Strindberg.