An under-deposit corrosion (UDC) sensor includes a probe body with a curved concave probe surface that may have pre-deposited or in-situ formed thereon a material that accelerates the process of under deposit corrosion. The UDC sensor uses electrochemically-based localized monitoring techniques for assessing under-deposit pitting corrosion and the effectiveness of chemical treatment programs that mitigate under-deposit corrosion in well tubing, pipelines, vessels, and/or tanks.