Titanium and its alloys are outstanding materials of choice, and their applications are rapidly growing worldwide in high-value markets such as aerospace, marine, power generation, heat exchangers, automotive and biomedical industries. They owe their popularity to their superior characteristics such as high strength to density ratio, also known as high strength to weight ratio or specific strength, as well as high corrosion resistance. Titanium alloys are used in aerospace industry to protect the fuselage, especially in military aircraft, from corrosion and heat damages caused by air friction in supersonic and hypersonic speeds. They are also widely utilized in marine industry to prevent corrosion from seawater or surrounding environment. Although titanium and its alloys are preferable materials by many design engineers, their poor machinability introduces a major drawback that plays a discouraging role in material selection decision. Machining titanium and its alloys requires extra care and attention to machine tool, cutting tool, and cooling strategy as the key elements of each machining system. The main objective is to prevent or minimize vibration, protect the tools from overheating and failure, and also achieve the desired dimensional accuracy and surface quality on the part. This chapter provides the readers with a brief review of the history of titanium, metallurgical aspects of titanium and the effect of alloying elements as well as their mechanical characteristics, and their industrial applications. This chapter also studies titanium and its alloys from machinability prospective in terms of mechanical behavior during machining, mechanics of chip formation, and appropriate cutting tools. The challenges and issues during machining titanium alloys will also be discussed in this chapter.