The rapid growth of the population had led the roadway paving industry worldwide to use sustainable alternatives to conventional road construction materials such as solid waste and recycled materials, thus contributing to sustainable development. The incorporation of such materials as a replacement of virgin materials has considerably been evolved, especially in asphalt concrete mixtures. The innovative use of secondary and tertiary materials is thus required as a replacement of conventional materials given that it will have no or minimal effect on the cost or the performance of the designed mixtures. Such practices are becoming more frequently used because of the depletion of natural conventional resources coupled with the rising demand for aggregates, the increase of waste production at an alarming rate, and the necessity of preserving raw sources. For this purpose, there has been a growing effort targeting the investigation of the possibility of upcycling and integrating of waste byproducts and other unconventional recycled materials as replacement of virgin materials in asphalt mixtures. The recycled materials might not possess the traditional recommended properties, and this might limit its use with caution or the need to follow different strategies to be tailored in specific with the characteristics of the material in use. In fact, several materials have shown satisfactory performance throughout the service life of the asphalt pavement as they own desirable properties over other materials. Despite that the exploitation of the feasible materials has led to new challenges on the paving industry. Bottom ash and fly ash are among the long list of unconventional and recycled materials in the practice that can be used as a replacement of conventional fillers in asphalt bituminous mixtures. Apart from the advantages of using waste materials, savings in cost, and environmental impacts, there are some aspects that need to be investigated targeting some performance-related issues. The ongoing research has been carried out for optimal incorporation of these materials in bituminous mixtures and flexible pavements from the top layer to the bottom layer. The work presented here aims at providing a review and compilation on the incorporation of bottom and fly ashes from municipal waste incineration as replacement of fillers in bituminous mixtures. This could cover the findings of research studies and practical experience covering methods to be followed and optimal incorporation scenarios taking into consideration various construction conditions, satisfactory applications, and long-term performance under the umbrella of adopting sustainable practices in the asphalt paving industry.