You don't say what your nationality is so the answer depends entirely on where you were born and what country issued your passport.
If you have a European EU passport, you don't need a visa no matter how long you are staying in Cyprus.
Other countries have an arrangement with Cyprus where no visa is required eg. Canada and the USA.
Please see my page on visa entry requirements for a full list of which countries require a visa. If you do need one, just ask your local embassy for the relevant forms.