Family name Ружичка (Ruzicka 
, Růžička 
, Ружичка 
) , in all the world, is a common cognomen. The last name Ружичка is habitual in Czechia, where it is a common surname, Slovakia, where it is quite a common surname, and Austria, where it is quite a rare surname. In absolute terms, this name is the most popular in Czechia, the United States, and Slovakia. Much less frequently, Ружичка is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ruzicka | United States, Germany, Czechia, Slovakia, Austria |
| Růžička | France, United States, Germany, Czechia, Austria |
| Ружичка | Russia, Kyrgyzstan, Ukraine |
| Ružička | Czechia, Croatia, Slovakia |