There are no tuition fees both for domestic and international students at Bielefeld University. All you have to pay is a social fee, which is currently about 300 EUR per semester. In return, you’ll receive your “semester-ticket”, which entitles you to use public transport (excl. high-speed trains) free of charge throughout North-Rhine-Westphalia (trips to Cologne, Düsseldorf, Bonn etc.). Besides this social fee, remaining costs including accommodation, personal expenses and health insurance, which is mandatory for all temporary and permanent residents in Germany. These costs are usually about 700-800 EUR per month. Non-EU-citizens will need to provide evidence that they have at least 10.236 EUR per year for the period of their stay to obtain a visa for study purposes from the German Embassy in their country (further information on visa regulations provides the DAAD).
Bielefeld University doesn’t provide any scholarships for international students for the whole study period, but sometimes announces (partial) scholarships for restricted time periods of usually one semester. See more on the website of the International Office. The International Office provides also information on various sources of financial support available to international students in Germany.