Historical data since 1950 and prospects for 2050 are presented here to show the trends of urbanization locally in the six Gulf Cooperation Council (GCC) countries as compared to the regional (Western Asia), and global counterparts. The trends are also examined for countries grouped based on their level of development (more developed, less developed, and least developed) and their level of income (high, upper-middle, lower-middle, and low). Countries with higher development level or income have more urbanization percentage than those with lower development level or income. Whereas Oman has consistently the lowest urbanization percentage among the GCC countries, it has the fastest urbanization rate during 1950-1995. The gap among all GCC countries is expected to decay, where all will have an urbanization percentage of 87% or more in 2050. The data presented here are predominantly based on processing row data published by the United Nations (UN) through its Department of Economic and Social Affairs (DESA).