Viktor Navorski (TOM HANKS) has traveled from his Eastern European country of Krakozhia to New York City with one purpose in mind. Yet, when his homeland erupts in civil war, he suddenly finds himself as traveler from a country the United States no longer recognizes.
As a result, airport security director Frank Dixon (STANLEY TUCCI) and head security guard Ray Thurman (BARRY SHABAKA HENLEY) try to inform Viktor that he can neither step foot on American soil or return to his homeland. Thus, Thurman takes Viktor to the international lounge, gives him some food vouchers and tells the foreigner -- who barely speaks any English -- that he must stay there until the situation in Krakozhia is resolved.
When Viktor sees footage of the civil war on the terminal TVs, he begins to understand what's occurred. Yet, when he loses his food vouchers to custodian Gupta (KUMAR PALLANA), he must figure out how to survive in this foreign environment. As Frank tries everything in his power to get rid of Viktor -- short of physically escorting him out -- the stranded traveler soon befriends various airport workers as he sets up his home away from home.
There's Enrique Cruz (DIEGO LUNA) who agrees to feed Viktor in exchange for him getting personal information about customs official Dolores Torres (ZOË SALDANA). Baggage handler Joe Mulroy (CHI McBRIDE) eventually convinces Gupta that Viktor is okay, while the latter falls for flight attendant Amelia Warren (CATHERINE ZETA-JONES) who occasionally passes through the airport.
As the days, weeks and then months pass, Viktor repeatedly adapts to his environment and Frank's repeated attempts to thwart him, all while waiting for the situation in his homeland to be resolved and trying to get Amelia to fall for him.