The dimunitive Slovakian, seeded 20th, delivered a powerful performance as she won the last eight games to wrap up the win in one hour.
Appearing in her first Grand Slam quarterfinal, 11th seed Halep was taught a harsh lesson by Cibulkova as she was pounded mercilessly from the back of court. The Romanian managed to win only 10 points in the second set.
Cibulkova, who defeated third seed Maria Sharapova in the fourth round, makes her second Grand Slam semifinal after the 2009 French Open. It is her best result in Melbourne since 2007, having bowed out in the second round the past two years.
She will meet the winner of the quarterfinal tie between two-time Aussie Open champion Victoria Azarenka and Agnieszka Radwanska.