Glyphosate has been a widely used herbicide since the 1970s. However, glyphosate causes serious health problems if exposed to it for a long time. Therefore, quick and reliable determination of glyphosate becomes an important issue. This study proposes a solution to this issue with a highly selective and sensitive fluorescent polymeric membrane sensor for glyphosate determination with a wide linear working range (1-18 ppb) and low detection limit (0.84 ppb). The developed sensor can measure glyphosate at pH 8.0 and is applicable to real samples with recovery percentages varying between 98.4 and 111.5. Additionally, this sensor can respond in a short time and can be reused up to 200 times. The repeatability of the method was found to be 10.47 ± 0.11 at a 95 % confidence level and the relative standard deviation was 1.76 for the analysis results of 10 ppb samples. All these features make proposed method, an ambitious alternative tool for glyphosate detection.