The model, who competed in the eighth series of the talent show, died in a hospice on Tuesday morning, according to TMZ.
Strauss had previously revealed she had been diagnosed with the disease on 2 October.
She wrote in a Facebook post: “I was gonna write some long thing but some of you guys deserve to know, on October 2nd I was diagnosed with stage IV breast cancer.
“It has aggressively spread throughout my body and is incurable. With treatment it may prolong my life longer than the ‘few months’ doctors said I could make it. I don’t want to die. I need another one of those miracles that I got back in 2013.”
Strauss had battled drug addiction during her life and celebrated five years of sobriety in August.
In October, she made a plea to her Instagram followers for support and prayers.
Strauss wrote: “I am scared. I really need your help – donations, kind words of support and prayers are completely welcome and absolutely needed. I have stage four metastatic breast cancer, and there is NO cure. “NO CURE?”
In a statement to TMZ, her family: “The one blessing was that we were able to show her how loved she was before she passed.
“She brought so much light to people.”