In this study, we focused on developing a new miniaturized solid-state contact PVC based iron(III)selective electrode using morin-Fe2+ shiff-base complex as the sensing material for environmental monitoring of iron (III) ions. The membrane composition of the electrode was optimized and the potentiometric performance characteristics of the electrode including selectivity, detection limit, pH range, response time, concentration range and potential stability were investigated. The results indicated that the electrode showed super Nernstian response of 56.14 +/- 0.22 mV/decade over the wide linear concentration range 1.0x10(-6) to 1.0x10(-1) M, and a very low detection limit of 4.5x10(-7) M. The potentiometric response of the fabricated electrode was independent at pH 5-10 and the electrode showed a very short response time (< 10 s). It exhibited excellent selectivity towards iron (III) ion over various cations including iron (II) ions. The proposed electrode was successfully applied for rapid inexpensive in-situ analysis of iron (III) ion in acid mine drainage and soil samples with comparison to inductively coupled plasma optical emission spectrometry (ICP-OES) analysis method, and the results obtained were agreeable with each other.