im travelling from the cayman islands to onatario canada... do i need a canadian visa?

yes,, all foreigners must have a visa (student,travel,business) fill one out at the air port ...when you leave to come to canada

yes

No you dont need a visa from the cayman islands to canada.

VISITOR VISA EXEMPTIONS
citizens of British dependent territories who derive their citizenship through birth, descent, registration or naturalization in one of the British dependent territories of Anguilla, Bermuda, British Virgin Islands, Cayman Islands, Falkland Islands, Gibraltar, Montserrat, Pitcairn, St. Helena or the Turks and Caicos Islands;