Fan Haifu (1933- ) is a native of Guangzhou, Guangdong Province. Fan is a crystallographer. He graduated from Chemistry Department, Peking University in 1956. He was elected as academician of Chinese Academy of Sciences (CAS) in 1991 and of the Third World Academy of Sciences (TWAS) in 2000. He served as part-time professor of Zhongshan University, China University of Science and Technology, and Peking University. Currently, he is a professor and a senior research fellow in Institute of Physics, CAS.

Fan engaged in research on crystallography. Fan led in determining crystal structure of new natural amino acids discovered by China, and he proposed the combination of direct methods with the heavy-atom method, the isomorphous replacement method and the anomalous scattering method for dealing with various kinds of "phase ambiguity" in single crystal structure analysis. The first combination led later to the direct method of solving superstructures.  While the last two combinations led to a hot topic in the study of direct methods since the 1980s till now. He called attention to new applications of direct methods and pointed out ways to go from the traditional field: (1) from single crystals to powder samples; (2) from small molecules to biological macromolecules; (3) from perfect crystals to imperfect crystals; (4) from X-ray crystallography to electron microscopy. In the following years Fan and his colleagues gained impressive results on three of the above topics. The study of direct methods for proteins led to new procedures, which manage to work with fewer experimental data and simpler manipulation. The application of direct methods to imperfect crystals resulted in direct methods of solving incommensurate modulated structures, which dose not rely on any assumed model. By applying his direct methods, he completed the research on the problem of pseudosymmetry in crystal structure analysis and developed a set of theory and application techniques. By introducing direct methods into electron microscopy, an image processing technique was developed together with Li Fanghua which combines high resolution electron microscopy with electron diffraction analysis enabling a single high resolution electron micrograph to be deconvoluted and enhanced to reveal individual atoms. As the result of a long-term international joint project, Fan co-authored a book with M. M. Woolfson titled Physical and Non-Physical Methods of Solving Crystal Structures, which has been published by Cambridge University Press in 1995. He has received the TWAS Award in Physics from the Third World Academy of Sciences in 1996, and Ho Leung Ho Lee Award for Science and Technology Advancement in 1998.