Titanium is a lightweight high-strength material with high corrosion resistance in many extreme environments, including saline and highly oxidizing conditions. These attributes make it an excellent material for specialized applications in aerospace, seawater service, biomedical implants, and chemical processing. The hexagonal α-phase offers the highest corrosion resistance, while the cubic β-phase affords high-strength with somewhat lower corrosion resistance. α-Titanium is immune to pitting corrosion, vapor phase corrosion, microbiologically-influenced corrosion, and stress corrosion cracking in aqueous solutions, but can be susceptible to crevice corrosion at temperatures above 70 °C under certain conditions. Hydrogen-induced cracking is a potential cause of failure when hydrogen atoms are a by-product of corrosion, although the ubiquitous oxide film generally acts as a strong barrier to hydrogen uptake by the metal. Small amounts of alloying additions or impurities (< 1 wt%) can have a profound influence on the microstructure, strength, and corrosion resistance of titanium. This chapter describes the metallurgical properties of titanium, the influence of environmental conditions (temperature, pH, chemical environment) on titanium corrosion, and the leading industrial applications of titanium materials.