Two-dimensional transition metal dichalcogenides (2D TMDCs) including MoS2, WS2, MoSe2, WSe2, etc., have received significant attention from the worldwide scientists for a variety of novel applications owing to their unique electronic, chemical, optical, and physical properties. This review focuses on the advances in the field of sensing based on 2D TMDCs and their composites. In this context, the recent progress of 2D TMDCs and their composites for lab-based detection of different analytes including heavy metals, biomolecules, hydrogen peroxide, toxic gases, and volatile compounds are discussed. Interaction of analytes with TMDCs and their composite is elucidated in accordance with various sensing mechanisms. Finally, the challenges and future opportunities related to the emerging 2D TMDCs and their composites based sensing devices are also presented. © 2020 Elsevier B.V.