If you are a GCC citizen: No entry visa is required.
If you are a citizen of one of the following countries, you will be issued with a free-of-charge visit visa upon entry: Australia, Andorra, Austria, Brunei, Belgium, Bulgaria, Canada, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary, Iceland, Ireland, Italy, Japan, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Malta, Monaco, The Netherlands, New Zealand, Norway, Poland, Portugal, Romania, San Marino, Singapore, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, United Kingdom, United States of America and the Vatican State.
If you are a citizen of any other countries, you will need to apply for a visa through your nearest UAE embassy. In some cases, your airline may be able to help you. An eye scan will be required at the airport.
Click here to visit the AD Airport Immigration and Visa site