It's an easy thing to get confused about, as the rules surrounding visas can be tricky at times. Your travel visa is a document that shows you're authorized to enter a particular country for a particular length of time, and for a very specific purpose. Most visitors to the United States need one to come into the country, but in what cases do US citizens need one to visit other countries? Again, the answer isn't a straightforward “yes” or “no”, as some countries require you to show a visa and others do not.
So Do I Need a Visa To Enter Turkey, Or Not?
The short answer? Yes. You will probably need a visa for entry into Turkey. Information from the U.S. embassy in Ankara clearly states that if you are planning to stay in Turkey for a period longer than three months, for any purpose, you must obtain a (Turkish Visa for US citizens) from a Turkish embassy or consulate to enter the country.
There are several methods for getting a Turkish visa, which include heading to a Turkish mission in the United States to apply for one, or using the online E-Visa system to make the application. Anyone heading to Turkey for tourism or commerce for a period lasting between 90-180 days, can use the E-Visa system to apply.
The Department of State also lists one exception to the Visa requirement:
“U.S. citizens who are traveling to Turkey by cruise ship are allowed to enter Turkey without a visa for a maximum period of 72 hours, with permission given by the local security authorities at the port of entry.”
According to the Department Of State, not only must your passport must be valid in order for you to enter Turkey, it must also have a two month “cushion” beyond the expiration date of your Turkish visa. Failure to comply with this requirement will deny you entry to Turkey outright, so it's an important rule to follow!
Also, if your visit requires a (Turkish Visa for US citizens), you will need to apply for a residence permit, work permit, or Turkish ID card within your first month in the country. You can obtain these permits by contacting the Foreigners Police in the area of Turkey you are visiting.
Follow The Rules, And Stay Safe
As The US Embassy is “unable to assist with Turkish immigration and visa related matters” it is important that when in Turkey, you follow the regulations to the letter. It should go without saying, but flagrantly violating another country's laws while you are a guest there is a surefire way to get hit with a hefty fine, deportation, and possibly being barred from the country.