The history of the Department of Computer Science can be traced back to the late '60s, when the University started to install her first main-frame computer which also marked the establishment of the Computer Centre. The mission of the Computer Centre was twofold, one in providing computing services to the University community , and the other in supporting teaching and research tasks in computer science. In '60s - '70s, where computers were still very rare and expensive, the Centre provided a number of service courses to all the disciplines in the University. In addition, the Centre also offered M.Phil. and Ph.D. degree programmes at that time. Below is a brief history of events of our department:
| 1969 | The Computer Centre, located in the Digby Building (1935), was established. The now demolished Digby Building was at the same location as the current Chow Yei Ching Building. |
| 1973 | The Computer Centre moved to the 8/F of Knowles Building, when it was built in 1973. |
| 1975 | Courses in Computer Studies were offered for the first time to students of the Faculty of Science. |
| 1978 | Dr. C.F. Chong graduated as the first M.Phil. student in Computer Studies. |
| 1981 | Computer Centre was renamed the Centre of Computer Studies and Applications (CCSA). Professor C.K. Yuen was appointed as the first Director of Computer Studies. |
| 1982 | The degree programme of B.Sc.(Computer Studies) was offered, in association with the Faculty of Science. |
| 1984 | The Centre of Computer Studies and Applications (CCSA) expanded and moved to the new Run Run Shaw Building. |
| 1985 | The first batch of B.Sc.(Computer Studies) students graduated. At the same time, two streams of study were offered: hardware-oriented programme and software-oriented programme. The "Hardware" stream students studied together with the B.Sc.(Engineering[Computer Engineering]) students. Professor Chorkin Chan was appointed as the Director of Computer Studies. |
| 1986 | The degree programme of B.Sc.(Computer Studies) was renamed B.Sc.(Computer Science). Professor Francis Chin was appointed as the Director of Computer Studies. |
| 1987 | Dr. Bethany M.Y. Chan graduated as the first Ph.D. student in Computer Studies. |
| 1988 | The Department of Computer Science was formally established in the Faculty of Engineering. The degree programme of B.Eng.(Computer Engineering) was jointly offered by the Department of Electrical and Electronic Engineering. Professor Francis Chin was appointed as the first Head of Department. |
| 1989 | The Department expanded rapidly and moved back to the 8th floor of Knowles Building at the end of 1989. |
| 1991 | The Information Systems Programme of B.Sc.(Computer Science) was first offered together with the Computer Science Programme. Moreover, a coursework postgraduate degree programme in M.Sc.(Computer Science) was first offered in the same year. |
| 1995 | The Department moved to Chow Yei Ching Building with an area of 1800 sq.m. The number of postgraduates in the Department grew to over 100, comprising 52 M.Phil, 24 Ph.D and 30 M.Sc.(C.S.) students. |
| 1996 | Additional laboratory space was assigned in Haking Wong Building. |
| 1997 | The Department expanded into Haking Wong Building with an additional area of 800 sq.m. |
| 1998 | The Department was renamed the Department of Computer Science and Information Systems on July 1, 1998. The degree programme of B.Sc.(Computer Science and Information Systems) was first offered in 1998. |
| 1999 | Launched a new MSc(Electronic Commerce & Internet Computing) degree programme from 1999-2000. |
| 2000 | The degree programme of B.Eng.(Software Engineering) was first offered together with the double degree programme B.B.A.(Information Systems)/B.Eng.(Software Engineering). Professor F.C.M. Lau was appointed as the second Head of Department. |
| 2001 | The degree programme of B.Sc.(BioInformatics) was first offered in collaboration with the Department of Biochemistry. |
| 2004 | The Department name changed from Computer Science and Information Systems to Computer Science with effect from July 1, 2004. |
| 2005 | A new B.Eng.(Computer Science) degree programme was launched to replace the B.Sc.(CSIS) and B.Eng.(SE) programmes. |
| 2006 | Professor D.W.L. Cheung was appointed as the new Head of Department. |
| 2012 | Professor W. Wang was appointed as the new Head of Department. |
| 2018 | Professor T.W. Lam was appointed as the new Head of Department. Jointly offered a new Master of Data Science (MDASC) degree programme with the Department of Statistics & Actuarial Science from 2018-19. |
| 2019 | A new BASc (FinTech) degree programme was launched from 2019-20. |
| 2021 | A new MSc(Financial Technology & Data Analytics) degree programme was launched from 2021-22. |
| 2022 | Launched a new BEng(Data Science & Engineering) degree programme and co-hosted the MSc(Artificial Intelligence) degree programme with the Department of Mathematics and Department of Statistics & Actuarial Science from 2022-23. |
| 2023 | Professor Yi MA was appointed as the new Head of Department. |