Jelena Karleusa Tosic (born 17 August 1978), professionally known under her maiden name Jelena Karleusa and initials JK, is a Serbian pop singer and fashion designer. She rose to fame with her debut album Ogledalce (1995), and has since been a popular Serbian female singer. She is married to football player Dusko Tosic, with whom she has two daughters.
Karleusa's latest single, "Insomnia", featuring Mirza Hamzic, was downloaded 1.5 million times from her website, just a day after its official premiere on the final night of the reality show Big Brother. "Insomnia" became the third most viewed video on YouTube, with over 4 million viewers for two weeks. The song is a cover of the Bollywood hit "Dance Pe Chance" from the film Rab Ne Bana Di Jodi.