La Castellana, officially the Municipality of La Castellana, is a municipality in the province of Negros Occidental, Philippines. According to the 20…La Castellana, officially the Municipality of La Castellana, is a municipality in the province of Negros Occidental, Philippines. According to the 2020 census, it has a population of 79,492 people. The town is named after the Paseo de la Castellana in Madrid, Spain.