William Ker

William Ker may refer to:


 * William Ker, Lord Ker (d. 1618), the eldest son of Robert Ker, 1st Earl of Roxburghe
 * William Ker, 2nd Earl of Roxburghe (d. 1675), Scottish nobleman
 * William Paton Ker (1855–1923), Scottish literary scholar and essayist
 * William Ker (footballer) (1852–1911), Scottish international footballer
 * William Balfour Ker (1877–1918), American illustrator