The Department of Physics which came into existence with the commencement of the Faculty in October 1967 is one of the eight academic departments belongs to the Faculty of Science of the University of Kelaniya. Since then the department has developed the academic programmes in physics, with the revisions of the syllabi in regular intervals, and improvements of the laboratory facilities.

In addition to physics, the Department offers electronics as a subject for the BSc (General) Degree programme of the Faculty of Science since the year 2000. Department of Physics at the University of Kelaniya is the first and only Physics department in Sri Lanka to provide facilities for BSc (General) Degree students to follow Electronics as a main subject in a Faculty of Science. At present the total student enrolment for physics and electronics courses is nearly 450.

The Department of Physics offers two BSc (Special) degree programmes; BSc (Special) degree in Physics and BSc (Special) degree in Mathematical Physics. BSc (Special) degree programme in Mathematical Physics is offered jointly with the Department of Mathematics and it is unique to the University of Kelaniya.