The incident occurred yesterday at the Benazir Bhutto International Airport near here when officials spotted the "blacklisted US citizen among the passengers who arrived from Kuwait Airways."
She was disallowed to check-out or leave the airport and later escorted to the same flight and deported.
It was not immediately known why her name was on the list of people blacklisted by Pakistan.
Relations between the US and Pakistan have been soured over concerns that people linked to CIA try to come to Pakistan posing as common citizens.