The dead 17-year-old French girl was part of a tour group of 54 teenagers from the Paris region who were on a trip to buy souvenirs in the market before heading home on Monday.
Most have been flown home but three remain in hospital, officials said.
French Foreign Minister Bernard Kouchner said he hopes the three can return to France on a hospital aircraft on Tuesday.
"There was a very powerful explosion. Then screams and blood. We all started running," said Romy Janiw, 28, one of the adults accompanying the teenagers.
It was the first deadly attack on tourists in Cairo since a bombing in the same neighbourhood killed two tourists and wounded 18 in 2005.
A series of bombings from 2004 to 2006 killed a total of 130 people in Red Sea resorts on the Sinai peninsula that were blamed on militants loyal to Al-Qaeda.
Sunday's attack took place outside a hotel across the square from the Hussein mosque, one of Egypt's oldest places of worship, and witnesses said the force of the blast shook the surrounding buildings.
It wounded 17 French tourists, one of them seriously, as well as a 37-year-old German, three Saudis and four Egyptians, officials said.
There were conflicting accounts about how the attack was carried out.
Witnesses and a police official told AFP two rudimentary bombs were thrown from a rooftop overlooking the street. The second device failed to detonate and was blown up in a controlled explosion, a police source said.
Kouchner, speaking on on the sidelines of a meeting in Brussels, said: "It is very disturbing to think that some people on the rooftops threw very deadly bombs at random into the crowd."
However, the prosecutor's office said a homemade bomb went off under a concrete bench, creating a 30 cm (one foot) crater and shattering the bench.
The attack drew condemnation from Muslim leaders and Middle East governments including regional heavyweight Saudi Arabia, whose nationals were among the wounded. Its rival Iran said the attack served only the interests of archfoe Israel.
The United States strongly condemned the attack. "We will continue to work closely with the government of Egypt to do what we can to support them in their efforts to fight terrorism," said State Department spokesman Robert Wood.
Sheikh Mohammed Sayyed al-Tantawi, head of Cairo's Al-Azhar University -- Sunni Islam's highest religious authority -- branded those who carried out the bombing as "traitors to their own religion and their nation."
Last year, 13 million tourists visited Egypt, earning 11 billion dollars in revenue. The industry also employs 12.6 percent of the workforce.
Egypt has been afflicted by violence throughout its modern history. President Anwar Sadat was assassinated by an Islamist group in 1981 and his successor Hosni Mubarak has been the target of a dozen attacks in 28 years in power.
The country lives under a state of emergency, allowing arbitrary detention, which has been repeatedly renewed pending finalisation of an anti-terror law.
