Olegas Truchanas (22 September 1923 – 6 January 1972) was a Lithuanian-Australian conservationist and nature photographer. He was a key figure in the attempt to stop the damming of the ecologically sensitive Lake Pedder in South West Tasmania by the Hydro Electricity Commission. His photographs, along with those of his protégé, Peter Dombrovskis, helped raise public awareness of the importance of the south-west Tasmania.