<p>The development of miniaturization and microfabrication technologies has rapidly diversified the field of electrochemical sensors. Electrochemical sensors provide many advantages, including cost-effectiveness, quick detection, and convenience. These sensors can detect various analytes and are broadly used for healthcare, agriculture, food safety, and environmental applications. In this review, we extensively discuss the fundamentals of various electrochemical sensing methods, the recent advancements in nanomaterials for the enhancement of electrochemical sensor performance, and their applications in different sectors. The electrodes fabricated with nanomaterials such as graphene, MXene, metal–organic frameworks, metal-based NPs, porous carbon, and conducting polymers display potential to enhance the limit of detection, detection time, selectivity, and sensitivity of electrochemical sensors. We also review the progressive applications and the importance of machine learning in electrochemical sensors. Finally, we discuss the existing challenges and possible remedies to encourage future developments in this field.</p>