The town of Frankfurt was founded in the 13th century (local government charter in 1253). The early settlers lived on the western banks of the Oder; later the town was extended to the eastern banks (which are today Polish). In late medieval times the town dominated the trade on the river between Wroclaw (Breslau) and Szczecin (Stettin). In 1430 Frankfurt joined the Hanseatic League, but was a member only for a short time.
Still in the 19th century, Frankfurt an der Oder played an important role in trade, centrally positioned in the Kingdom of Prussia between Berlin and Posen, today's Poznan in Poland, and on the trafficked river Oder. The city housed the 2nd largest annual trade fair (Messe) of the German Reich, surpassed only by that in Leipzig. This is in sharp contrast to the Frankfurt an der Oder of the Cold War.
After World War II Frankfurt was located at the new Polish border; the quarters on the eastern banks became the Polish town of Slubice. Both towns are now in friendly relations and run several common projects and facilities. After Poland's joining the European Union on May 1, 2004, Frankfurt an der Oder is no longer a border town.
Frankfurt housed a university between 1506 and 1811. A new university was opened recently in 1991: the Viadrina University, which is a common German-Polish university.
Frankfurt an der Oder is not to be confused with another city called Frankfurt, the much larger Frankfurt am Main.