While there are several analytical models dedicated to the vertical IGBT there is virtually no reliable model for the Lateral IGBT (LIGBT). LIGBTs are increasingly popular in smart power and power integrated circuits, especially in those applications where high voltage and high current capabilities are required. Silicon on insulator (SOI) could be the future technology for power devices and integrated circuits due to its much improved device isolation. In this work we report for the first time a complete analytical model for the SOI LIGBT based on semiconductor physics with very few fitting parameters. The model is assessed against finite element device simulations and experimental results