Most Germans have the day off from work on Wednesday to celebrate the national holiday, which marks the country's unification 22 years ago.
This year, the official festivities are being hosted by Munich and the premier of the southern state of Bavaria, Horst Seehofer kicked off the proceedings on Tuesday, one day ahead of the national holiday.
Each of Germany's 16 states is represented at the festivities in the Bavarian capital.
Both President Joachim Gauck and Chancellor Angela Merkel are to be among more than 1,500 dignitaries attending the central celebrations in Munich this Wednesday, which began with an Ecumenical religious service in St. Michael's church.
'European cooperation necessary'
In a speech at an official ceremony in the Bavarian State Opera, the president of the Bundestag, Norbert Lammert, from Merkel's Christian Democrats, called for more cooperation in Europe.
"In Europe today, we no longer have to pull down any walls, but to unite Europe we need prudent and farsighted policies," he said.
He also stressed the progress that had been made since the Berlin Wall that separated West from East Germany was removed, saying that "the successes and achievements of Germany unity are clearly visible."
Smaller-scale events were planned for Wednesday across the country.
As has been the case every October 3 since 1997, Germany's Muslims will be reaching out to the rest of the population by opening the doors of more than 600 mosques to the general public. The theme of this year's initiative, which is organized by the Coordinating Council of Muslims, is "Islamic Art and Culture."
Germany's national holiday has been held on October 3 since that day in 1990, when the former German Democratic Republic (East Germany) joined the Federal Republic of Germany, to form a single unified state.
pfd,tj/ch (dpa, dapd)