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

Aspen Hill
Baltimore
Columbia
Dundalk
Ellicott City
Frederick
Germantown
Hagerstown
Ilchester
Joppatowne
Kettering
Laurel
Montgomery
North Bethesda
Odenton
Potomac
Queenland
Rockville
Silver Spring
Towson
Urbana
Vienna
Waldorf
(no X)
Yarrowsburg
Zihlman