Rajna is a surname. In several Eastern European languages such as Hungarian, Rajna is the name of the river Rhine. Notable people with this surname include:
* András Rajna (born 1960), Hungarian sprint canoer
* Daniel Rajna (born 1968), South African ballet dancer
* Mihály Rácz Rajna (born 1934), Hungarian stage actor
* Miklós Rajna (born 1991), Hungarian ice hockey goaltender
* Rajna DragiÄeviÄ, Serbian linguist, lexicologist and lexicographer
* Thomas Rajna (1928â2021), British composer