Infobox last updated on: 14 July 2008.

Gréta Arn (born 13 April 1979; in Budapest, Hungary) is a professional tennis player from Hungary, who previously represented Germany. Arn turned professional 1997.

In her career she won four ITF titles in singles and in doubles; she also won her first WTA title in Estoril, in Portugal, on 6 May 2007. Her career high on WTA rankings was No.81, on 22 July 2002.