| Date | Districts | Incumbents | Elected senators | Cause |
|---|
| 1999 Prague 1 by-election | Prague 1 | Václav Benda (ODS) | Václav Fischer (NK) | Death |
| 2003 Czech Senate by-elections | Strakonice, Brno-City District | Pavel Rychetský (ČSSD), Dagmar Lastovecká (ODS) | Josef Kalbáč (KDU-ČSL), Karel Jarůšek (ODS) | Incompatible office: Elected to the Constitutional Court |
| 2004 Czech Senate by-elections | Prague 4, Znojmo | Josef Zieleniec (SNK ED), Vladimír Železný (NK) | František Příhoda (ODS), Milan Špaček (KDU-ČSL) | Incompatible office: Elected to European Parliament |
| 2007 Czech Senate by-elections | Chomutov, Přerov | Petr Skála (NK), Jitka Seitlová (NK) | Václav Homolka (KSČM), Jiří Lajtoch ČSSD | Resignation and Incompatible office: Elected to European Parliament |
| 2011 Kladno by-election | Kladno | Jiří Dienstbier (ČSSD) | Jiří Dienstbier Jr. (ČSSD) | Death |
| 2014 Zlín by-election | Zlín | Tomio Okamura (Dawn) | Patrik Kunčar (KDU-ČSL) | Incompatible office: Elected to the Chamber of Deputies |
| 2014 Prague 10 by-election | Prague 10 | Jaromír Štětina (TOP 09) | Ivana Cabrnochová (Green Party) | Incompatible office: Elected to European Parliament |
| 2018 Trutnov by-election | Trutnov | Jiří Hlavatý (ANO 2011) | Jan Sobotka (STAN) | Incompatible office: Elected to the Chamber of Deputies |
| 2018 Zlín by-election | Zlín | František Čuba (SPO) | Tomáš Goláň (Senátor 21) | Resignation |
| 2019 Prague 9 by-election | Prague 9 | Zuzana Baudyšová (ANO 2011) | David Smoljak (STAN) | Resignation |
| 2020 Teplice by-election | Teplice | Jaroslav Kubera (ODS) | Hynek Hanza (ODS) | Death |
