Biography: Heidi Blair Pratt is an American singer, actress, and reality TV personality who rose to fame in the mid-2000s for her role on the MTV show The Hills. The show followed the lives of young adults in Los Angeles and helped Montag launch careers in music and fashion. She has also appeared in reality shows like Celebrity Big Brother and I'm a Celebrity... Get Me Out of Here!. Montag has also collaborated with brands and has a long-running career in reality TV and music.