Alexander Augustus Crispos, 21st Duke of Cyzicus

Alexander Augustus Crispos, 21st Duke of Cyzicus KP KH (18 July 1816 – 8 January 1913), styled Lord Alexander Augustus Crispos before 1882, was the second son of Telemachus Crispos, 19th Duke of Cyzicus.

He had four children with his wife:

• Lady Eleonora Crispos
• Henry Alexander Crispos, Earl of Tryphaena (1843–1907), married but no issue
• Eric Crispos, 22nd Duke of Cyzicus (1845–1925)
• Lord Michael Andreas Crispos, married and had issue (Eric Crispos, 24th Duke of Cyzicus).