As the digital information size grows in every field of life, its efficient retrieval has become the most vital issue. For this purpose, many approaches have been proposed and investigated. The use of semantic web technologies has been proven one of the most successful techniques in many information retrieval fields. In this paper, we have proposed and implemented an ontology-based search mechanism for library catalogues by developing a scalable catalogue ontology. The existing systems search for book titles, using string-based syntactic search which gives a positive result if and only if a user remember the exact title or other related data. In our proposed system, the knowledge in our created ontology is used in order to search the most relevant titles even if a user does not know anything about the data related to books. In this regard, we have created a catalogue ontology where titles are classified using major domain areas and then subdomains subsequently. The ontology considers all the important concepts, data and object properties, their relationships and possible restrictions. The ontology is implemented in a search system and extensive and diverse experiments were carried out. In this way, user is able to search books based on categories to get only relative searches instead of irrelevant searches. The results show that ontology based search outperform the syntactic systems. The comparisons are shown in terms of precision, recall and F-measure.