The term "Weimar Triangle" refers to a loose grouping of Poland, Germany, and France. The group is intended to promote co-operation between these three countries. It exists mostly in the form of summit meetings between the leaders of these three conferences, the most recent of which occurred on May 9th 2003 in Poland. Previous meetings occured in Poznan, Poland (1998), Nancy, France (1999), and Hambach, Germany (2001). The Weimar Triangle also involves lower-level connections, such as the annual meeting between Foreign Ministers.

The most recent leaders' summit was hosted by President Aleksander Kwasniewski of Poland and attended by President Jacques Chirac (France) and Chancellor Gerhard Schroeder (Germany). A joint statement praised the Weimar Triangle arrangement for "further strengthening the ties of cooperation between the three nations and states at all levels and in all areas."

The Weimar Triangle was established in the German city of Weimar in 1991, aimed at assisting Poland's emergence from Communist rule. Attending the meeting were the Foreign Ministers of each state: Roland Dumas of France, Hans-Dietrich Genscher of Germany, and Krysztof Skubiczewski of Poland.