  In this work, we aim to show the possibilities of the variable speed of light
(VSL) theory in explaining the type Ia supernovae observations without
introducing dark energy. The speed of light is assumed to be scale factor
dependent, which is the most popular assumption in VSL theory. We show the
modified calculation of the distance modulus, and the validity of the
redshift-scale factor relation in VSL theory. Three different models of VSL are
tested SNe data-sets with proper constraints on the model parameters. The
comparison of the three models and flat $\Lambda$CDM in distance modulus is
showed. Some basic problems and the difficulties of the confirmation of the VSL
theory are also discussed
