The Secular Democratic Front (SDF) is an opposition front in the Indian state of Tripura consisting of the Left Front and the Indian National Congress which formed before the 2023 Tripura Legislative Assembly election in opposition to the incumbent Bharatiya Janata Party government. The main parties in this coalition are the Communist Party of India (Marxist) and the Indian National Congress along with other minor parties in the Left Front. This is currently the official opposition in Tripura Legislative Assembly.