Tendering management is a large and fragmented process implemented in various industries such as construction, logistics, pharmaceutical, and commerce. Tendering process is vital for a governing body that intends to acquire any goods or services from third parties for ensuring fair and transparent competition. Current electronic tender management does not have the necessary capabilities to automatically extract unstructured information on the tender document and hence, requires the decision maker to examine the information contained on the document one by one. In addition, the isolated tendering process leads to the ineffective communication between different stakeholders such as owners/clients, consultants, and contractors/suppliers to share and reuse information especially during decision-making. The increasing inconsistent and semantic heterogeneity information for the decision-making process requires the need to represent knowledge in a uniform format that is understandable to both humans and computers. Thus, the ontology-based decision support system architecture for tendering management is proposed to support information extraction and decision-making process. A prototype of ontology-based decision support system is developed using the case study of the construction tender evaluation process.