MXenes are two–dimensional layered materials of early transition metal carbides and/or nitrides applied in multiple scientific applications ranging from catalysis, energy storage, to sensors owing to their fascinating and technologically useful properties. This review presents an overview of the current state–of the–art progresses in the field of electrochemical (bio) sensors for the detection of biomarkers, pharmaceutical drugs, and environmental contaminants. Firstly, how synthetic strategies and surface functionalization affect various properties of MXenes, and consequently, the sensing performances are highlighted. Secondly, MXenes as an electrode modifier for the detection of pharmaceutical drugs, environmental contaminants, and important disease biomarkers such as cancer biomarkers, glucose, hydrogen peroxide, etc., are well discussed. Finally, challenges in this field with possible solutions and future opportunities are discussed. •Synthesis of MXenes and their functionalization strategies are discussed.•Current state–of the–art progresses in the field of MXene–based electrochemical (bio) sensors are reviewed.•Detection of disease biomarkers, pharmaceuticals, and environmental contaminants are highlighted.•The analytical performances of these sensors are compared with literature, and their strength/weaknesses are discussed.•Present challenges with possible solutions and future research opportunities are discussed.