The paper provides an overview of the literature on Circular Economy (CE) theoretical approaches, strategies and implementation cases. After analyzing different CE approaches and the underlying principles the paper then proceeds with the main goal of developing tools for CE implementation. Two tools are presented: a CE Strategies Database, which includes 45 CE strategies that are applicable to different parts of the value chain and secondly a CE Implementation Database, which includes over 100 case studies categorized by Scope, Parts of the Value Chain that are involved, as well as by the used Strategy and Implementation Level. An analysis of the state of the art in CE implementation is also included in the paper.