The scientific and analytical value of soil and sediment evidence in criminal and civil procedures is examined in this chapter. Often disregarded, soil and sediments are rather special molecules with important associative evidence connecting a suspect or object to a specific location. Starting with a definition of soil and sediment, this chapter addresses its composition, methods of formation, and classification depending on physical, chemical, biological, and geological criteria. It notes their use in forensic settings—including buried remains, aquatic environments, and terrestrial crime scenes—as well as the basic distinctions between soil and sediment. Essential to maintaining the integrity of soil and sediment samples, the chapter provides a complete review of the chain of custody, preservation, and collection techniques. Priority one is reducing contamination, highlighting stratigraphy and collecting control soil samples for a comparison study. Microscopic inspection, mineralogical profiling, chemical characterisation (pH, elemental analysis, ICP-MS, AAS), biological markers (pollen, spores, microorganisms), and experimental techniques like FTIR and SEM-EDS are among the advanced analytical techniques that are then covered. Additionally, introduced is the use of geographic information systems (GIS) and geospatial techniques in forensic soil analysis. Using case studies and pragmatic applications, the chapter shows how soil and sediment evidence has proved crucial in settling a range of crimes, from sexual assault and murder to environmental breaches and illegal dumping. The subject addresses the reconstruction of crime scene dates depending on sediment deposition patterns and the evidential value of dirt transfer on shoes, clothes, tools, and automobiles. The chapter also evaluates critically the challenges and restrictions in forensic soil and sediment analysis, including the need of standardised processes, sample heterogeneity, and environmental changes. It also highlights fresh advances using metagenomics, artificial intelligence, and data-driven soil databases that are increasing the accuracy and dependability of forensic interpretations.