Cognomen กช (Kot 
, Koj 
, กช 
) , in the entire world, is a common last name. The cognomen กช is habitual in Poland, where it is quite a common surname, Macao, and Hong Kong, where it is quite a rare surname. Not in comparison with a country's population, it most frequently occurs in Poland, India, and the United States. Also, กช is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kot | Egypt, India, Taiwan, United States, Poland |
| Koj | Germany, Czechia, India, United States, Poland |
| กช | Thailand |
| Korchan | Russia, India, United States, Poland, Slovakia |
Ghodchaphak, Khutpakan, Khutphab, Koch, Kochawhan, Konchuearat, and Korchakun
ยวธน, อิงสุธรรม, วงเวียน, จากภัย, ตัญญะวังรัตน์, อามระดิษฐ์, พุทธยากูล, อุบลชลเขตต์, เยาว์ธานี, ธนวัชรางกูร, ยุทธนาปกรณ์, and สวัสดิ์วงษ์