Okay so im planing to go to turkey in a couple of weeks to see my boyfriend. Im from the United states, and i read that you could get your visa in the Istabul Airport, Is it time consuming? or is it a better idea to get it before i go?  Also what documents would i need to get married? I cant find the name of the one that shows proof that im not already married...or even if it exists here.

Thanks so much for your help

 Yes Gul, you could get visa in the Istanbul Airport, Once you arrive at the airport its easy to get visa. There are counters that issuing visas, you get in line and wait for your turn to come. Make sure you got the exact amount of money at the counter. The immigration officer will stamp sticker type of visa on your passport and will give you receipt. Sometimes you might wait long at the que but its much easier way than trying to get visa while you are in America.

Conditions for a Valid Marriage
Capacity to marry: Only those persons who have sufficient mental capacity to make fair judgments are allowed to marry. Mental illness is, therefore, a bar to marriage. In addition, a person must have reached the minimum age of 18 to marry.
Absence of consanguinity: Marriage between close relatives is prohibited
Already existing marriage: Monogamy is one of the essential principles of Turkish family law. A second marriage cannot be entered into unless the first is terminated. A divorcee should produce legal documents (i.e.: A Court Sentence about the termination of her/his previous marriage) in order to marry again.
Waiting period: Married women whose marriage has been dissolved cannot marry before the expiration of three hundred 300 days from the date of dissolution. The divorce decree may also state a waiting period within which the guilty spouse may not remarry.
Sickness: Certain sicknesses, such as epilepsy, hysteria, venereal and contagious diseases, constitute a bar to marriage in Turkey.

Only civil marriages performed by authorized marriage officers are allowed in Turkey.
Necessary Documents for Marriage
1. Four (4) copies of the petition of the marriage. To start an action, the groom and the bride must submit a petition of the marriage. This is called Evlenme Beyannamesi
2. Identification such as: Passport, Identification card or Birth Certificate
3. Health certificate (If demanded by one of the parties)
4. 6 passport size photos of the bride and the groom.
5. Certificate of capacity to Marry. (Single, divorced, widow or widowed) (For foreigners the certificate of no impediment can be obtained from the relevant Embassy or Consulate which then needs to be authenticated by the local Governor office in Turkey

 (Certificate of Capacity to Marry (Certificate of Celibacy), which states if a person is single, divorced, or widow. To be taken from the proper Civil Status Register of his/her own country. If this Certificate is to be issued in the country of the foreigner then it should be certified by the Turkish Consulate or Embassy there or it should have an apostil. It should also be translated into Turkish and notarized, otherwise it will not be valid )

 Just one little point: Gul you say you are coming from US, not whether you are a US citizen or not. Visa requirements depend on your citizenship, and which passport you have. Agree with the above comments for US, UK, Ireland, Canada, NZ, Australian passport, but not all countries citizens can buy one at the airport.

yu may want to check out this site gul: 

http://turkey.usembassy.gov/visa_requirements.html

Information for Travelers

Visa Requirements

American citizens traveling to Turkey on U.S. passports must obtain a visa. Currently, holders of all types of passports can purchase a 90-day sticker visa at the port of entry for $20 cash if they are traveling to Turkey as tourists. For further information, travelers in the U.S. may contact the Embassy of the Republic of Turkey at 2525 Massachusetts Avenue, NW, Washington, D.C. 20008, telephone: (202) 612-6700, or the Turkish consulates general in Chicago, Houston, Los Angeles, or New York. Information may also be found at Internet address http://www.turkey.org. Overseas, travelers may contact a Turkish embassy or consulate.

Holders of official and diplomatic passports on official business must obtain a visa from a Turkish embassy or consulate before arrival in Turkey.

All travelers planning to stay more than three months for any purpose are required to obtain a visa from a Turkish embassy or consulate. Such travelers must also apply for a residence/work permit or Turkish ID card within the first month of their arrival in Turkey. This includes anyone who plans to spend more than three months doing research, studying, or working in Turkey.

The Embassy is unable to provide any information regarding the renewal or extension of Turkish visas. Holders of such visas are encouraged to contact Turkish authorities.

Visas are 20 USD (cash only).  Once you get off the plane you will go to the Visa window.  They will give you your visa.  Then you get to stand in line to have the Turkish immigration officer stamp your visa.  (This part can take up to an hour, sometimes more)

There is no longer a waiting period if you are divorced but you will have to bring your documents with you if you are divorced.  Also, your divorce documents will need to be brought to either the American Consulate in Istanbul or the America Embassy in Ankara to have them authenticated.  In other words, the consulate/embassy has to guarantee that your divorce is legal.  Once you have the signature of the consulate, you will take that document to the local Turkish governors office to have the consulate signature authenticated.  Its a really pain in the butt!  It will go faster if you make an appointment at the American Consulate/Embassy.  If you have never been married, then you will just tell them you have never been married. There is no document for that.  

Have your fiance call the local marriage office where you intend to get married.  Some requirements for marriage or LOCAL requirements.  For example, many local marriage offices will REQUIRE you to hire a certified translator if you are not fluent in Turkish.  Your fiance might be able to find one by inquiring in a Notary Office (thats where we found ours).  

Also the health examination is really just bloodwork to prove that you do not have any contagious disease and that you are immune to others (like measles, mumps, rubella).  Some marriage offices require it...others don´t.

Just keep in mind that all of this costs money.  I don´t recommend calling the American consulate about requirements for marriage in Turkey.  I would ask local Turkish government officials.  Only they know the latest changes (laws change very quickly in Turkey and they don´t always inform all the foreign dignitaries).  Good luck...hope this was helpful.

I was married in Turkey some years ago and was shocked at the differences between what the American consulate told me and what the local Turkish government authorities told me.  

Good luck!