The 128th Delaware General Assembly was a meeting of the legislative branch of the state government, consisting of the Delaware Senate and the Delaware House of Representatives. Elections were held the first Tuesday after November 1 and terms began in Dover on the first Tuesday in January. This date was January 2, 1973, which was two weeks before the beginning of the third administrative year of Governor Sherman W. Tribbitt and Eugene Bookhammer as Lieutenant Governor.

Currently the distribution of seats for both houses was based on the interpretation of the federal 1970 census. It resulted in a large numbers of membership numbers in the New Castle County area and ruling that the election districts would abandonment of county lines for their boundaries, but would design whatever district boundaries that would accomplish such population equals.

In the 128th Delaware General Assembly session both chambers had a Democratic majority.

• Hoffecker, Carol E. (2004). Democracy in Delaware. Wilmington, Delaware: Cedar Tree Books. ISBN 1-892142-23-6.
• 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