Oskar Krejčí (born 13 July 1948 in Prague) is a Czech political scientist, the author of approximately thirty books and more than thousand articles in the area of political science. Krejčí is a director of the Institute of the Global Studies of The Jan Amos Komensky University Prague, Czech Republic. He is a vocal critic of the plans of the Bush administration to install a national missile defense system on the territory of the Czech Republic and Poland.