Public prosecutors have charged Thaksin under Section 112 of the Criminal Code and the 2007 Computer Crime Act. The charges stem from an interview he gave to South Korean media in 2015, in which he allegedly made remarks deemed offensive to the monarchy.
Thaksin has denied all allegations and is currently out on bail.
The court has scheduled full-day hearings from 9am to 4.30pm over the three days. Thaksin is required to attend the hearings in person each day.
His lawyer, Winyat Chatmontree, confirmed briefly that Thaksin would appear in court tomorrow.