Do I have to pay FICA tax if I am a full time employee for an Emerati company?
I know I have to pay income tax but what about FICA tax?

I live in the UAE and working full time as an employee for an Emerati owned company. I know I have to pay income tax as a US citizen but do I still need to pay FICA.

I got this from the iRS website,

Social Security and Medicare Tax for Persons Employed by a Foreign Employer

U.S. Citizens, Resident Aliens, and Nonresident Aliens employed outside the United States by a foreign employer are not generally subject to Social Security and Medicare tax withholding. However, an American employer with a foreign affiliate may request that Social Security and Medicare taxes be withheld from the U.S. citizen and resident alien employees of the foreign affiliate by filing Form 2032, Contract Coverage Under Title II of the Social Security Act.

As noted by the IRS website citation, you are NOT obligated to pay FICA (Social Security and Medicare) taxes while working for an overseas company in a foreign country.

The option to have FICA taxes withheld applies ONLY IF the employer is a foreign affiliate of a U.S. company. That does not apply in your case.