This study aspires to reveal the background of the penetration of solar thermal technologies and to overview the past and present of solar thermal systems as well as their potential and the market in the Baltic States. In this study a review of the solar energy potential and the market in Baltic states is conducted. The study presents the types of solar thermal systems, their cost, the progress of installations in recent years as well as the potential of solar thermal systems in Lithuania, Latvia, and Estonia. A comprehensive review and analysis of medium-scale solar thermal systems in Baltic states is also presented. The study also discusses on the current support financial schemes for solar thermal energy valid in the investigated EU member states. Despite the long payback period of ST systems in Baltic countries, the market is slowly growing, mainly due to support from EU and other funds.