Timber is one of the most sustainable and renewable raw materials available. Globally, it has been increasingly used for the manufacture of home and workplace furniture. Timber products are known to have ignition resistance and a low heat release rate. These characteristics delay burning and maintain the structural durability of a product, protecting both the occupants and their properties in a fire. Timber, however, experiences thermal degradation during combustion, yielding smoke, heat, toxic gases, and char when burned. To understand the fire conduct of timber, extensive knowledge in its process of decomposition is essential. This paper, therefore, reviewed the methods of flammability tests widely employed to investigate the reaction of timber and timber-based product to fire, namely cone calorimeter test, room-corner test, limiting oxygen index (LOI) test, furnace test, and single burning item test (SBI). In addition, an overview of the fire retardant treatments; impregnation and coatings was also presented. The potential effects of fire retardants on the durability, strength, hygroscopicity, corrosion, machinability, glueing characteristics, and paintability of the timber were also highlighted.