If you are talking about the Italian spelling of Roma (Roma), I found these cities. So, there should be one in each continent.
# Roma, Queensland, a town in Australia
# Puerto Roma, Ecuador, a town in Ecuador
# Roma, Botoşani, a town in Romania
# Roma, Sweden, a town in Sweden
# Roma, Texas, a town in the United States
# Roma, Lesotho, a town where the National University of Lesotho is situated
https://en.wikipedia.org/wiki/Roma
This question has been asked on other internet pages. Someone in this page says there is no Roma, Australia.
http://msgboard.snopes.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=47;t=000452;p=0
From this page it looks like Roma, Queensland is an airport, not a city.
http://www.wunderground.com/global/stations/94515.html