A non-governmental organization (NGO) is a non-profit, citizen-based group that functions independently of government. NGOs are organized on local, national and international levels to serve specific social or political purposes.

As non-profit organizations, NGOs rely on a variety of sources for funding projects, operations, salaries and other overhead costs. Because the annual budget of an NGO can be in the hundreds of millions (or even billions) of dollars, fundraising efforts are important for the NGO's existence and success. Funding sources include membership dues, the sale of goods and services, private sector for-profit companies, philanthropic foundations, grants from local, state and federal agencies, and private donations.

Individual private donors comprise a significant portion of NGO funding. Some of these donations come from wealthy individuals, such as Ted Turner's $1 billion donation to the United Nations, or Warren Buffett's 2006 pledge to give 10 million Berkshire-Hathaway class B shares to the Bill and Melinda Gates Foundation (valued at more than $31 billion in June 2006). Many NGOs, however, rely on a large number of small donations, rather than a small number of large donations.

Despite their independence from government, many NGOs rely heavily on government funding to function. Some governmental NGO funding may be viewed as controversial because the funding may support certain political goals rather than a nation's development goals. (For related reading, see: What is an NGO (non-governmental organization)?)