Recent years have seen increasing initiatives involving more open strategizing. These initiatives, referred to as Open Strategy, imply greater transparency and/or inclusiveness in strategy processes (Hautz et al., 2017; Whittington et al., 2011). As such, Open Strategy forms part of a larger societal trend toward greater degrees of openness in all domains of life – such as Open Innovation (Chesbrough, 2003), Open Source Software (von Hippel & von Krogh, 2003), Open Government (Janssen et al., 2012), Open Data (Huijboom & van den Broek, 2011), and Open Science (David, 1998). By comparison with some of these domains, research on Open Strategy is still nascent. While substantial theoretical groundwork has been laid, and both qualitative and quantitative studies are now appearing, there remain significant opportunities for more research on what is a fast-developing and wide-ranging set of initiatives. Given this breadth, we identify the key dimensions, practices, and impacts of Open Strategy, and propose promising theoretical perspectives capable of building cumulative knowledge regarding these. We also guide researchers by offering a practical definition that sets boundaries on the phenomenon.