Delfzijl is a city and former municipality with a population of 25,651 in the province of Groningen in the northeast of the Netherlands. Delfzijl was a sluice between the Delf and the Ems, which became fortified settlement in the 16th century. The fortifications were removed in the late 19th century. Delfzijl is the fifth largest seaport in the Netherlands, and the largest port in the North East of the country.

Eemsdelta is a municipality in the province of Groningen, Netherlands formed from the merger of Appingedam, Delfzijl and Loppersum. The municipality came into existence on 1 January 2021.