Concepts are the most basic units which act as building blocks in Artificial Intelligence research. They play a key role in Knowledge Representation (e. g., in semantic networks, conceptual graphs, description logics), All these approaches focus on other aspects of concepts, leading to different formalizations A concept is determined by a collection of objects (extent) which fall under the concept and a collection of attributes (intent) covered by the concepts. Here we focus on two formalizations, namely Ontologies and Formal Concept Analysis. In particular, we will discuss how Formal Concept Analysis can be used to support Ontology Engineering. Here we are focusing on the two main activities of ontological engineering: designing an ontology and merging of ontologies. In this chapter we have discussed the use of formal concept analysis in designing an ontology and merging of ontologies. © 2017, Indian Journal of Public Health Research and Development. All rights reserved.