William Duhurst Merrick (October 25, 1793 – February 5, 1857) was a United States Senator from Maryland, serving from 1838 to 1845. Merrick was born in Annapolis, Maryland and completed preparatory studies. He later graduated from Georgetown University in Washington, D.C..Merrick held several local offices and served in the War of 1812. He was the register of wills of Charles County, Maryland from 1825 to 1832.