Yes, Tina, a passport is required to fly into Cancun. Not sure if you are a U.S. citizen, but here is what is says on the U.S. Department of State website: "Since March 1, 2010, all U.S. citizens – including children – have been required to present a valid passport or passport card for travel beyond the “border zone” into the interior of Mexico. The “border zone” is generally defined as an area within 20 to 30 kilometers of the border with the U.S., depending on the location. Regardless of the destination in Mexico; however, all U.S. citizens age 16 or older must present a valid U.S. passport book or passport card to re-enter the U.S. by land. A passport book is required to return to the United States via an international flight." http://travel.state.gov/travel/cis_pa_tw/cis/cis_970.html