The 1999 Warsaw Cup by Heros singles was the singles event of the fifth edition of the Warsaw Open; a WTA Tier IV tournament held in Warsaw, Poland. Conchita Martínez won the tournament last year when it was a Tier III event. She did not compete this year.
Cristina Torrens Valero won her first WTA tournament, defeating Inés Gorrochategui in the final 7–5, 7–6(7–3).