This study presents a low-cost Arduino-based gas chromatography system that is suitable for teaching analytical chemistry in an undergraduate laboratory. The gas chromatography system is built with commonly available materials with a total cost less than $100. A Python code is also provided as a user interface that will record data and display the results in real-time. The functionalities of the gas chromatography system are demonstrated with the detection of in-house natural gas, product gases from a CO2 reduction, and a noble gas. Step-by-step instructions for building the gas chromatography system and detailed explanation of the Python code are provided in the Supporting Information for this paper. The goal of this project is to provide a low-cost and versatile GC platform where undergraduate students can modify each individual component of a GC and study the underlying principle of separation science in analytical chemistry.