According to a filing, her resignation was not the result of any disagreement between her and the company.
Former Diageo Canada CEO
Kelly-Ennis, former president and CEO of Diageo Canada, had served on the Carnival boards since 2012.
The filing did not state whether Carnival intends to appoint a new director.
The 11 directors are Carnival Chairman Micky Arison, President and CEO Arnold Donald, Sir Jonathon Band, Jason Glen Cahilly, Helen Deeble, Dick Glasier, Katie Lahey, Sir John Parker, Stuart Subotnick, Laura Weil and Randall Weisenburger.