The diverse applications and widespread effects of cyberspace in most military and civilian applications have led to the rapid growth of data, information, knowledge, technology, methods, tools, and cyber systems. One of the important and strategic requirements in the cyber Command and Control cycle is the capability to extract, process, fusion and analyze data and information from various sources to achieve the desired situational awareness of the cyberspace and cyber operations environment. Considering the various aspects of this issue, the use of soft data, ie data and information from human resources, along with hard data, ie data and information of machine resources, can help in achieving more accurate and reliable recognition and decision. One of the main research topics in this area is designing a conceptual model and appropriate processing framework for analysis and inference based on data and information with the ability of linking various information from different sources with each other and modeling different types of uncertainty in hard and soft data and fusing them. This paper presents an ontology-based approach to the processing and fusion of hard and soft data in cyber Command and Control, in which various aspects of the issue has been addressed including ontology-based architecture and processing framework of information inference and fusion, the method of representation of uncertainty and reliability in hard and soft data and fusing these data, conversion of beliefs into probabilities to be able to make decisions on the hypotheses under consideration, designing an appropriate ontology model for cyber Command and Control purposes, and design and implementation of ontology-based logic of inference and fusion. The results of applying the proposed model in a typical scenario of cyber Command and Control show that it is operational in fusion of hard and soft cyber data. In addition to the ability of inference and fusion, one of the notable features of the proposed approach is its scalability and adaptability to new extensions in the tools and requirements of cyber Command and Control.