Llangwyllog railway station was situated on the Anglesey Central Railway line from Gaerwen to Amlwch. The single storey station building with ticket and waiting room was located on the Down (west) side and opened in 1865, the platform being extended in 1890. A small goods shed was located north of the main building. In 1914 a passing loop was installed at the station, the only one of the whole Anglesey Central line. Another platform was also installed in the year on the opposite side of the line which had a wooden shelter on it.