Opinion polling for the 2021 Czech parliamentary election started immediately after the 2017 parliamentary election. Monthly party ratings are conducted by Sanep, TNS Kantar, STEM and CVVM.
Poll results are listed in the tables below in reverse chronological order, showing the most recent first. The highest percentage figure in each polling survey is displayed in bold, and the background shaded in the leading party's colour. In case of a tie, then no figure is shaded. Poll results use the date the survey's fieldwork was done, as opposed to the date of publication; however, if this date is unknown, the date of publication is given in its place. There is an electoral threshold of 5% for political parties.