The 1970 United States Senate election in Maryland took place on November 3, 1970. Incumbent Democratic U.S. Senator Joseph Tydings ran for re-election to a second term, but was narrowly defeated by Republican U.S. Representative J. Glenn Beall Jr.
Tydings had defeated Beall's father, Senator James Glenn Beall six years earlier. Tydings's own adoptive father Millard had served as senator as well as Beall Sr., making this a rare dynastic election between the sons of former senators.
, this was the last time a Republican won the Class 1 Senate seat in Maryland.