When we want to find experts on the Web we might want to search where the knowledge is created by the users. One of such knowledge repository is Wikipedia. People expertises are described in Wikipedia pages and also the Wikipedia users can be considered experts on the topics they produce content on. In this paper we propose algorithms to find experts in Wikipedia. The two different approaches are finding experts in the Wikipedia content or among the Wikipedia users. We also use semantics from WordNet and Yago in order to disambiguate expertise topics and to improve the retrieval effectiveness. In the end, we show how our methodology can be implemented in a system in order to improve the expert retrieval effectiveness.