In this study, simple and fast linear sweep voltammetry method was developed and validated for determination of olanzapine in pharmaceutical preparations. The proposed method was based on electrochemical oxidation of olanzapine on glassy carbon electrode in solution containing 0.04 M Britton-Robinson buffer of pH 1.65. The well-defined an oxidation peak was observed at 1.06 V.  The calibration curve was linear for olanzapine at the concentration range of 2.5-50 µg/mL for linear sweep voltammetry method. Intra- and inter-day precision values for olanzapine were less than 4.78, and accuracy (relative error) was better than 1.85%. The limits of detection and quantification of olanzapine were 0.50 and 1.50 μg/mL, respectively. The mean recovery of olanzapine was 99.8% for pharmaceutical preparations. Stability measurements were carried out with linear sweep voltammetry method. The results were evaluated comparing these measurements with those of standards and expressed as percentage deviation and olanzapine was found as stable at room temperature, 4 and -20 °C for at least 72 h. No interference was found excipient at the selected assay conditions. The voltammetric run time of 1 min allows the analysis of a large number of samples in a short period of time. The proposed method is highly sensitive, precise and accurate and can be used for the reliable quantitation of olanzapine in pharmaceutical dosage form