Cognomen Герардус (Gerardus 
, Geradus 
, Герардус 
) , worldwide, is quite a rare family name. The family name Герардус is habitual in Cyprus, where it is quite a rare surname, Hungary, and Spain, where it is a rare surname. Not in comparison with a country's population, it is the most numerous in Indonesia, Spain, and Hungary. More frequently, Герардус is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Gerardus | Germany, Indonesia, South Africa, Spain, Netherlands |
| Geradus | Indonesia, South Africa, Spain, United States, Netherlands |
| Герардус | Russia, Ukraine |
Geert, Gellert, Gellért, Gerald, Gerallt, Gerard, Gerardo, Gerd, Gerhard, Gerhardt, Geri, Gerold, Gerrit, Gert, Giraldo, Girard, Gérald, Gérard, Herardus, Гелерт, Геллерт, Геральд, Геррит, Герт, Герхард, Джеральд, Джерард, Джерард, Жерар, Джерардо, Жерар, Жеро, Херардо, ג'ראלד, ג'רארד, גרהרד, ז'ראר, جيرار, جيرارد, جيرالد, غيرت, ジラード, 吉拉德, and 杰拉德