Saudi Arabia

Population & Expat Population (per CIA World Factbook): 26,534,504, of which an estimated 5,576,076 are non-nationals.

Or, as reported in the Saudi Gazette on Nov. 24, 2010, the 2010 census showed 27,136,977 people dwelling in the Kingdom, of which 18,707,576 were Saudis (9,527,173 males and 9,180,407 females), and 8,429,401 foreign workers, of whom 5,932,974 were men and 2,496,427 were women.

United Arab Emirates

Population (per CIA World Factbook): 5,314,317

Expat population: Approximately 75-80% of the population is made up of expatriates.

Qatar

Population (per CIA World Factbook): 1,951,591

Expat population: Not sure, but most estimates say that 75-80% of the population are expats.

Kuwait

Population & Expat Population (per CIA World Factbook): 2,646,314, of which an estimated 1,291,354 are non-nationals