With the increase in population, the concern with food production combined with good crop management practices has been prioritized in the agricultural environment. One of the methods that stands out in this segment is production in greenhouses, where it is possible to control internal climatic factors, generating products with added value. With the advent of computer technologies, applications aimed at agriculture have grown exponentially, such as the use of sensing and artificial intelligence techniques, transforming these environments into intelligent places. Although there are a number of technological devices that can be used to improve the environmental aspects of greenhouses, these domains must be created in a structured way, so that it represents the knowledge involved between all agents and parameters. Considering these aspects, this study proposes an ontology-based model for smart greenhouses. To achieve this goal, it searches the literature for existing ontology models and implements, using the Prótége software, the classes and relationships of this domain. As a result, the ontology proves to be a facilitating tool in the creation of conceptual models that serve as a knowledge base and representation of cultivation environments in smart greenhouses, expressing aspects of the real world.