Participation of citizens in the process of city development is very important. To achieve good governance and democratic, the citizen can participate by providing complaints, information, or advices. In the current system, complaints are handled manually by 1-2 operators, whereas speed and accuracy are needed. The problem is this manual handling causes errors in the determination of appropriate government departments that handle the complaint. This research will propose a system that aims to determine the appropriate government department with complaints given by the citizen with the implementation of K-Nearest Neighbor (KNN) algorithm, to reduce human errors. This algorithm is one of text classification algorithms, which in this research, is used to classify complaints which the texts in Indonesian language. The input of the system is complaint given by the citizen and the output is the name of the appropriate government department, which is in accordance with the contents of the complaint.