  Recently, a new geometric approach which is called the fixed-circle problem
has been gained to fixed-point theory. The problem is introduced and studied
using different techniques on metric spaces. In this paper, we consider the
fixed-circle problem on $S$-metric spaces. We investigate existence and
uniqueness conditions for fixed circles of self-mappings on an $S$-metric
space. Some examples of self-mappings having fixed circles are also given.
