The name of the town was derived from a plant called 'Dilaw', a type of shrub that can be found within the town. The origin of the Municipality of Marilao is closely linked with the political and cultural history of Meycauayan City. In fact, Marilao was just one of the barrios surrounding the Municipality of Meycauayan established by the Franciscans in 1578.
Due to Meycauayan's high rate of population growth and rapid pace of its economic advancement, one by one, the large barrios separated from the mother town and became individual municipalities. Among these barrios is the duly constituted Municipality of Marilao established on April 21, 1796.
The very first town church was constructed in a place known as Tawiran. The old chapel however, has stood 50 years before. On October 20, 1888, the municipal building was constructed beside the old chapel.
The inauguration of the first locomotive in the Philippines has brought Marilao the benefits of modern telegraph communications system together with other nine towns near Manila. However, it was not until March 24, 1889 that railroad construction was completed.
The creation of a separate town hastened the development of Marilao relative to other Municipalities in the province.
At present, Marilao has a total Land Area of 3,374 hectares. As of 2014 it has a population of 223,664 and consisted of 16 Barangays, namely: Abangan Norte, Abangan Sur, Ibayo, Lambakin, Lias, Loma De Gato, Nagbalon, Poblacion I, Poblacion II, Prenza I, Prenza II, Saog, Sta. Rosa I, Sta. Rosa II, Tabing-Ilog and Patubig.
Municipality of Marilao continues to excel in different manners, not only for inter-municipal but also outside the Province of Bulacan.