In this paper, we introduce and study the concept of one-local retract in modular function spaces. In particular, we prove that any commutative family of r-nonexpansive mappings defined on a nonempty, r-closed and r-bounded subset of a modular function space has a common fixed point provided its convexity structure of admissible subsets is compact and normal. MSC: Primary 47H09; Secondary 46B20, 47H10.