Culprit identified as Ala'a Badr Abdullah al-Hashemi was given death sentence for killing Romanian-born Ibolya Ryan, a mother of 11-year-old twins, in the rest room of Al Reem Island in Abu Dhabi, news agency Reuters reported.
Al Reem Island is a residential, commercial and business project on Al Reem Isle, a natural island 600 m off the coast of Abu Dhabi island.
She also planted a bomb outside the home of an American-Egyptian doctor.
According to reports, Hashemi was also convicted of setting up a social media account to spread militant ideology with the intention of undermining the government and, and of giving money to militant organisations for attacks.
Police said last year Hashemi had become radicalised over the internet and had not been targeting an American in particular, but was looking for a foreigner to kill at random.
UAE an opponent of Islamist groups joined joined air strikes in Syria against the Islamic State group, which has urged Muslims in Gulf countries to target Western expatriates in retaliation for attacks against it.