**Abstract**

Among novel techniques, laser welding is considered an adaptable and rapidly evolving method, finding innumerable applications in engineering industries. It is capable of welding narrow and impassable joints precisely, which can be operated under computer control. This chapter of the welding Handbook reviews the most recent developments in the field of laser welding, which are used for different applications. The first section provides an overview of laser welding basics and then moves on to the developments such as high-power CO2 laser welding, laser micro-welding, and solid-state laser welding technologies. The second section underlines laser welding instruments used for joining different materials such as titanium, aluminum, and magnesium alloys, ceramics, and plastics. The third section highlights the advances in innovative laser welding methods with discussions on the applications of laser welding robots to improve the modeling and simulation of this technique. Lastly, the fourth section focuses on the use of laser welding technology in various industries including aerospace, automotive, railway, etc. The present Handbook is a practical reference for scholars, engineers, and professionals using laser welding techniques or requiring an understanding of the field of laser welding technologies.

**Keywords:** laser welding, CO2 laser welding, laser micro-welding, solid-state laser welding
