Nehemiah Mayo Dyer (19 February 1839 - 28 January 1910) was a Rear Admiral in United States Navy during the Civil War and Spanish-American War.
Born in Provincetown, Massachusetts, Dyer entered the Navy as master's mate in 1862 and was promoted to acting ensign and acting master for gallant service aboard Metacomet during the Battle of Mobile Bay, 4-5 August 1864. He won additional laurels while commanding the cruiser Baltimore in the Battle of Manila Bay 1 May 1898. Rear Admiral Dyer died in Melrose, Massachusetts, 28 January 1910.
USS Dyer (DD-84) was named in his honor.