The University is a founding member of Universitas 21, a network of comprehensive research intensive universities covering all corners of the globe. One of the main objectives of Universitas 21 is to assist in the aspiration of its members to become global universities and to advance their plans for internationalisation.

The HKU Worldwide Undergraduate Student Exchange Programme, established in 1997, enables over ten per cent of our undergraduate student population to undertake exchange at institutions overseas or in Mainland China. Its close links with 150 partner institutions in 19 countries worldwide serves to enhance students' global perspective and foster cross-cultural understanding among students of participating institutions.

While the University is fostering the concept of a worldwide classroom, the academic collaboration and bonding with the universities in the Mainland remain close. The HKU Worldwide China Programme has actively involved students to participate in different academic and internship programmes with the most prestigious universities and corporations in Mainland China to develop cross-disciplinary skills. The key universities that the University closely works with include Tsinghua University, Peking University, Fudan University, Shanghai Jiao Tong University, Zhejiang University, Nanjing University, Xiamen University and Sun Yat-sen University, on undergraduate student exchange and joint postgraduate programmes. The first batch of undergraduates admitted to the University on a scholarship scheme graduated in 2002.

Following a new Hong Kong government policy, the University expanded since 2002 its original scheme for the admission of undergraduates from the Mainland with Scholarships to cover students who are not supported by scholarships. For the year 2006-2007, the university admitted 267 fee-paying mainland students from the 10,231 who applied. HKU is the most popular Hong Kong university choice of mainland students and its popularity among mainland applicants received positive media coverage in the recent years.

The University currently offers joint master programmes in mainland China in collaboration with prominent universities in Shanghai, Shenzhen, and Chongqing. These joint programmes include master degrees in business administration, social work, social service management, real estate, construction project management and finance.

HKU has many on-going research connections with institutions and universities around the world. One of the most notable international collaborative efforts is the HKU-Pasteur Research Centre. Established in 1999, the Centre combines the interests of both the University and the Institut Pasteur in battling infectious diseases. HKU also signed a memorandum of understanding in the summer of 2002 to set up a twin research centre with the Aaron Diamond AIDS Research Centre in New York. In January 2003, the first ever human Genome Research Centre was established in Hong Kong together with the Hospital for Sick Children (HSC) of Toronto (an affiliation of the University of Toronto, Canada).

The World Trade Organisation (WTO) recognises HKU as a leading tertiary education institution in Asia. In 2004, HKU was selected as the official WTO training centre for the Asia-Pacific Region, and has since been running regional trade policy courses for government officials from over 30 jurisdictions in the region.