As the Functionally graded (FG) material is most likely to be utilized under high thermal environments, the free vibration analysis, a fundamental dynamic characteristic, of FG folded plates under thermal environment holds significant importance to understand their mechanical behaviour and potential applications. Modal analysis of all side clamped (CCCC) FG folded plates is done considering First order transverse shear deformation theory (FSDT). Power law variation and temperature dependent material properties are considered. A finite element program in MATLAB environment is developed for the present study applying folded plate transformation considering 8-noded elements. The investigation explores the impact on natural frequency due to the change in crank angle, thickness, temperature field (uniform/linear temperature rise), and gradient index. The findings have undergone validation against reputed publications.