In the 2024 census, the population of Cabusao was 18,882 people, with a density of .
Religion The municipality is composed of two Catholic parishes, the San Bernardino de Siena Parish and the San Pascual Baylon Parish. Every barangay hold its own barangay fiesta to honor their village patron saint. During that event, the village is lavishly decorated, especially the route of the processions. The Roman Catholic Church and the local authorities work side by side for a glorious and memorable fiestas. Although there is a separation of church and state, as stated in the country's constitution, the Catholic Church as an institution occupies a very high position in the society. The present pastoral program is geared toward organizing and strengthening the SKK (saradit na kristiyanong komunidad) which means BEC, basic ecclesial community. Rev. Fr. Apolinar "Yonyon" Rull Napoles Jr.organized the housing projects for the victims of typhoon "Reming" ( International name Durian). There are two new villages in the place called Dusayan Village (Caritas International) and the San Rafael GK (Gawad Kalinga) Village, both located in the north-east of barangay Castillo. Among the non-Catholic religions are the Iglesia ni Cristo,
Ang Dating Daan,
Jesus Miracle Crusade and very small number of mainline Protestants. The parish of St. Bernardine of Siena was founded in 1914. The Feastday is every 20th day of May. The following is the list of parish priests: ==Economy==