The 5th Delaware General Assembly was a meeting of the legislative branch of the state government, consisting of the Delaware Legislative Council and the Delaware House of Assembly. Elections were held the first day of October and terms began on the twentieth day of October. It met in Dover, Delaware, convening October 20, 1780, and was the third year of the administration of President Caesar Rodney.

The apportionment of seats was permanently assigned to three councilors and seven assemblymen for each of the three counties. Population of the county did not effect the number of delegates.

• Martin, Roger A. (1995). Memoirs of the Senate. Newark, Delaware: Roger A. Martin.

• Delaware Historical Society; website; 505 North Market Street, Wilmington, Delaware 19801; (302) 655-7161
• University of Delaware; Library website; 181 South College Avenue, Newark, Delaware 19717; (302) 831–2965