The 18-year-old McDonald's worker was evicted from the Elstree compound over fellow finalists Aaron Allard-Morgan and Jay Mckray.
"Well done huns," she said to the boys, as she squealed her way up the stairs.
Alex left the house in a sparkling pink dress to the tune of Aqua's 'Barbie Girl' and continued to happily scream as she spotted loved ones in the crowd and met host Brian Dowling.
Rose has long been bookies' favourite to win Channel 5's first series of the competition.
Louise Cliffe earlier became the first person to leave tonight's final, while Tom O'Connell finished fifth in a surprise eviction yesterday.
Watch Alex Rose's Big Brother best bits below: