The meeting will be the second test of interfaith relations after a visit to Cologne's synagogue, where Benedict was warmly received by Jewish officials for his remarks urging better Jewish-Christian relations and warning of rising anti-Semitism.
Reaching out to Jews and Muslims is one of the main themes of his trip, along with his effort to evangelise a Europe that many think is forgetting its Christian heritage.
Benedict will be greeted at the meeting by Rydvan Cakir, president of the Turkish-Islamic Union of the Institute of Religion, a social and religious group. About 2.6 million people of Turkish origin live in Germany.
Since becoming pope, Benedict has steered a cautious course on Islam, saying little besides condemning the bombings in London as the work of "fanatics" who don't represent true Muslim faith.
Some Turks were dismayed when he became pope because of remarks he made in his earlier role as the Vatican's chief of doctrine on the nature of multiculturalism and specifically about Turkey's aspirations to join the European Union.
He has said that multiculturalism is "fleeing from what is one's own" and urged Europe to return to its Christian roots, alarming some who see Turkey's future as part of a religiously diverse Europe.
He said in an interview with the French publication Le Figaro that "Turkey has always represented a different continent, in permanent contrast to Europe".
The pope has been given a warm
welcome in his home country
On Saturday morning, Benedict met with German Chancellor Gerhard Schroeder and the chancellor's challenger in 18 September elections, Angela Merkel. Both are Protestants.
After the meetings, Benedict was to move to the Marienfeld, a former coal mine outside Cologne for an outdoor evening service as part of World Youth Day, the Catholic youth festival that has drawn more than 400,000 young people.
Many of them made plans to come when John Paul II, the founder of the festival, was alive and are eager to get to know his successor.
So far, Benedict has cut a less theatrical figure than John Paul, not making such grand gestures as kissing the ground on arrival, and reading his speeches in a soft voice that sometimes didn't carry over the sound of the wind.
But he's been greeted with jubilant applause, chants and shouts each time he appears in public.
Many of the pilgrims at the Saturday vigil are expected to spend the night under the open sky to attend Sunday morning's concluding Mass celebrated by Benedict.
Organisers say they expect as many as one million to attend.