Fluoride is the world’s most abundant element and is naturally present in water, air, plants, and animals. Fluoride in low concentrations (<1.5 mg/L) in groundwater has a beneficial effect on strengthening bones and preventing tooth decay. It is currently becoming a significant environmental pollutant, which is rapidly evolving due to industrial emissions and agricultural activities like using fertilizers. However, excessive occurrence of fluoride in groundwater may lead to tooth decay, osteoporosis, and damage to the kidneys, bones, reproductive organs, nerves, and muscles. This book chapter focuses on assessing various fluoride sources in groundwater, including natural geological and anthropogenic sources. In addition, special emphasis has been made on the geochemical characterization of fluoride sources using different electrochemical, chromatographic and spectroscopic methods and statistical correlations between fluoride concentrations with other measured parameters like pH, electrical conductivity, TDS, etc. This study provides valuable information for researchers and policymakers seeking information to solve the problem of fluoride pollution and to promote sustainable water management practices.