Greece–Turkey relations

Greece and Turkey established diplomatic relations in the 1830s following Greece's formation after its declaration of independence from the Ottoman Empire. Modern relations began when Turkey was proclaimed a republic in 1923 following the defeat of the Ottoman Empire in World War I. Rivalry has characterised their relations for most of their history with periods of positive relations but no underlying resolution of the main issues.

Control of the eastern Mediterranean and Aegean seas remains as the main issue. Following the aftermath of World War II, the UNCLOS treaty, the decolonisation of Cyprus, and the addition of the Dodecanese to Greece's territory have strained the relationship. Several issues frequently affect their current relations, including territorial disputes over the sea and air, minority rights, and Turkey's relationship with the European Union (EU) and its member states—especially Cyprus. Control of energy pipelines is also an increasing focus in their relations.