Czechization or Czechisation (Czech: čechizace, počeštění; German: Tschechisierung) is a cultural change in which something ethnically non-Czech is made to become Czech.

This concept is especially relevant in relation to the Germans of Bohemia, Moravia and Czech Silesia^{[citation needed]} as well as the Poles of Trans-Olza^[1] who have come under increased pressure of Czechization after the breakup of Austria-Hungary and the formation of a Czechoslovak nation state in 1919 (see Germans in Czechoslovakia (1918-1938)); to a smaller extent, it has also occurred with Slovaks and Rusyns.^{[citation needed]}

With the expulsion of the majority of Germans and the partial resettlement of previously German-speaking parts of Czechoslovakia by Czechs, these territories became czechized after World War II.

"In June 1905, the German language paper Bohemia of Prague reported czechization in Saxony, Germany after a great influx of Czech workers had czechified the town of Ostritz.^[2] According to Saxon officials, the reports were greatly exaggerated.^[2] They conceded that while Czech speakers in Saxon communities were fewer than popularly supposed, they were nevertheless worth watching."^[2]

• Demographics of Czechoslovakia
• Demographics of the Czech Republic
• Germans in Czechoslovakia (1918-1938)
• Poles in Czechoslovakia
• Ruthenians and Ukrainians in Czechoslovakia (1918-1938)
• Slovaks in Czechoslovakia (1918–1938)