Joseph Davies Tydings (né Cheesborough; May 4, 1928 – October 8, 2018) was an American lawyer and politician. He was most notable for his service as a Democratic member of the United States Senate representing Maryland from 1965 to 1971. Tydings also argued Eisenstadt v. Baird, in which the Supreme Court of the United States legalized birth control for single persons in 1972, something that had been prohibited in many states. The Eisenstadt decision has been described as among the most influential Supreme Court decisions of the 20th century.