The 27-year-old eccentric singer took on the character made famous by Judy Garland during a live performance of her new track 'Applause' on breakfast show Good Morning America.
Gaga started her performance by altering the lyrics to her track, singing: "I live for your applause, should we make our way to Oz?"
Dressed in Dorothy's iconic blue checked dress, the singer was joined by a scarecrow, tin man and lion as she danced down a yellow brick road, later emerging from behind a green curtain dressed this time as the Good Witch Of The North.
Another costume and hair change saw her embodying the Wicked Witch, before she emerged with her own unique take on Dorothy's outfit: a big-shouldered, blue striped jacket and oversized bow in her hair.
Gaga fans had been expecting an Oz-themed performance as she announced on Twitter last week she'd be embracing her inner Dorothy for a theatrical performance.
She also tweeted: "When Dorothy goes GLAM / snatches all the weaves of OZ / outsmarting the Wicked West / as she thrills for your APPLAUSE!"
'Applause' is the first track taken from Gaga's upcoming album ARTPOP.
Watch Lady Gaga's 'Applause' video below: