The alphamegalog of the cities of North Dakota lists the largest city in North Dakota for each letter of the alphabet. In this case, ‘largest’ is based on population within the city proper.

Ashley
Bismarck
Casselton
Dickinson
Ellendale
Fargo
Grand Forks
Horace
(no I)
Jamestown
Kenmare
Lincoln
Minot
New Town
Oakes
Park River
(no Q)
Rugby
Stanley
Tioga
Underwood
Valley City
West Fargo
(no X)
Ypsilanti
Zap