Public diplomacy, a term which entered the International Relations (IR) lexicon in the 1960s in the US, has been a major tool of foreign policy statecraft over the last half century. This chapter briefly traces the history of the study of public diplomacy in the field of Foreign Policy Analysis. First, the chapter elaborates how the phenomenon and study of public diplomacy can be connected to IR theories. After that, it will explain how we can categorize the statecraft of public diplomacy and how they can be studied, especially with newly emerging methodological tools such as quantitative text analysis and online survey experiments. The chapter argues several research agendas ahead of us, who do Foreign Policy Analysis in IR.