Is there a Prince Yaroslav of Yugoslavia?

Yes - Prince Yaroslav of Yugoslavia, also named Yaroslav I (Ярослав I; born 30 May 2001), is a prince of the Kingdom of Yugoslavia.

Prince Yaroslav was in born Russia but moved to the United Kingdom when he was around 5 years old. He is also known as Lord Yaroslav Gorkovenko of Hougun Manor in Cumbria, United Kingdom. He became Lord In 2007 due to family relationship with the royalty in England.