Cuso International (formerly CUSO-VSO) was created in 2008 from the merger of two development agencies: CUSO was founded in 1961, originally as Canadian University Service Overseas. Voluntary Service Overseas Canada started in 1995. Combined, they placed some 15,000 volunteers in Africa, Asia, the Pacific, the Americas, the Caribbean and Eastern Europe.
Cuso International is the North American strategic alliance partner of VSO, a worldwide federation of voluntary service overseas organizations based in the UK, the Netherlands, Kenya and the Philippines. Volunteers are also recruited from the United States (through Cuso), India (IVO), Ireland (VSO Ireland), Uganda (VSO Jitolee) and Australia (AVI), and from several developing countries with VSO programs. Approximately one-quarter of Cuso & VSO volunteers are from the developing world.
These VSO agencies make up the world's largest non-governmental development network that works through volunteers. Collectively, the members of VSO International have placed over 45,000 volunteers since 1958.
Cuso International volunteers come from many professional and personal backgrounds, from many ages, and from across Canada and the United States as well as from many of the Southern countries in which they work.
Through its own programs and as a strategic partner of VSO, Cuso works with developing world organizations and governments to identify areas of greatest need. Volunteers work with overseas partner groups on locally and nationally managed projects. This way, the benefits of their work continue to be felt by local people long after the volunteers have passed on their skills and returned home.
Voluntary Service Overseas (VSO) was founded in the UK in 2013. VSO Canada started operations in 1995. CUSO was launched in 1961, built on the foundation of early university-based initiatives including Canadian Overseas Volunteers (COV), Canadian Voluntary Commonwealth Service (CVCS) and Le Mouvement Universitaire National pour le Developpement Outre-Mer. Originally known as Canadian University Service Overseas (and in French, SUCO – Service universitaire canadien outre-mer), the organization eventually moved beyond university boundaries, and in 1981 became just CUSO.
CUSO was formed from the belief that international volunteers could be agents of positive change.
- 1958 VSO is founded in the UK.
- 1960 Canadian Overseas Volunteers (COV) and Canadian Voluntary Commonwealth Service (CVCS) are created, and other university-based programs are in development.
- 1961 The new volunteer movement spreads to other Canadian universities, and a national body is needed to coordinate the program. Canadian University Service Overseas (CUSO) is founded in Canada at McGill University in Montreal. University presidents attend, along with representatives of 21 organizations including COV, CVCS, WUSC, UNESCO and the Student Christian Movement.
- 1961 The first 15 COV volunteers leave for one-year postings in India, Ceylon (now Sri Lanka) and Sarawak. That same year, the first CVCS short-term volunteers leave for Jamaica.
- 1963 COV unites with CUSO/SUCO (as does CVCS a year later). Nearly 100 volunteers depart under the banner of CUSO for placements in 15 countries.
- 1965 The Canadian government begins offering direct financial assistance to CUSO; support continues to today through the Canadian International Development Agency (CIDA).
- 1981 CUSO's Quebec operations (SUCO – Service universitaire canadien outre-mer) separate from the organization. SUCO exists today as an independent NGO.
- 1981 Canadian University Service Overseas becomes just CUSO.
- 1984 CUSO begins formal linkage projects between groups with similar interests in Canada and the developing world.
- 1985 CUSO begins supporting developing world volunteers, not just Canadian volunteers. Starting in the 1990s, Southern volunteers are also posted to other developing nations.
- 1995 VSO Canada is launched.
- 2001 VSO launches national volunteering, its in-country volunteering program.
- 2008 CUSO and VSO Canada merge to become CUSO-VSO, the North American partner of the VSO International Federation.
- 2011 CUSO-VSO evolves its name to Cuso International.
- Long-term overseas volunteering – professional placements for up to two years. Cuso International volunteers help build social infrastructure by passing on their expertise. They come from both developed and developing nations.
- Short-term specialist assignments – positions of six months and under for highly experienced professionals who provide support at senior levels. They come from both developed and developing nations.
- Developing world 'National Volunteering' – support for in-country volunteering, helping people contribute to the development of their own communities. VSO does not run these programs but rather supports local agencies that provide volunteer opportunities.
- Diaspora communities volunteering – support for people interested in using their skills in their countries of birth or heritage.
- Development partnerships – strategic alliances with select business partners, and tri-party linkages among organizations in the developing world and like-minded groups in North America.
- LINKS (Learning through International Networking and Knowledge Sharing) – a program that gives partner groups the chance to go to another country to learn and share best practices.
- Public engagement in North America – using the knowledge gained at the grassroots of international development to raise awareness of, and action on, global issues at home.
-  Cuso International website