In this study, we introduce a very sensitive and selective method for the differential pulse anodic stripping determination of Sb(III) ion on the over-oxidized poly(phenol red) modified glassy carbon electrode (PPhRed(ox)/GCE) in 0.1 mol L-1 HCl medium. The formation of both poly(phenol red) and over-oxidized poly(phenol red) film on the electrode surfaces were characterized by electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy techniques. An anodic stripping peak of Sb(III) was observed at 0.015V on the PPhRed(ox)/GCE. Higher anodic stripping peak current of Sb(III) was obtained at PPhRed(ox)/GCE compared with both bare GCE and poly(phenol red) film modified GCE (PPhRed/GCE). The calibration graph consisted of two linear segments of 0.044 - 1.218 g L-1 and 3.40 - 18.26 g L-1 with a detection limit of 0.0075 g L-1. The proposed over-oxidized polymer film modified electrode was applied successfully for the analysis of antimony in different spiked water samples. Spiked recoveries for water samples were obtained in the range of 93.0-103.0%. The accuracy of the method was also verified through the analysis of standard reference materials (SCP SCIENCE-EnviroMAT EP-L-2).