No visa required
Citizens of Denmark, Finland, France, Germany, Japan, New Zealand, Norway(only official passport holders), Sweden and Switzerland can enter Turkey for up to three months with a valid passport.
Visa on arrival
Citizens of Australia, Belgium, Canada, Greece, Ireland, Italy, Netherlands, Portugal, Spain, UK and USA can enter Turkey for up to three months whereas citizens of Norway, Hungary and many Eastern European and Central Asian countries can enter for up to one month with a purchase of a visa sticker on arrival.
Note that your passport must have at least three months’ validity remaining. Turkish lira, Euros and US dollars are accepted for visa fees.
The Electronic Visa Application System replaces the sticker and stamp type visas formerly issued at the border crossing. Applicants can obtain their visa electronically after entering required information and making payment by credit card. For more information you can check the official website of e-Visa.
There are single and multiple entry visa options. Single entry visas are valid for three months, while multiple-entry visas are valid for three month blocks during a one-year period. Depending on your nationality, it is possible to extend visas. For more information please check the website of Ministry of Foreign Affairs. http://www.mfa.gov.tr/default.en.mfa