The 40-year-old "Open Book" author and fashion designer revealed on Monday that she'd received a positive result on a COVID-19 test at some point over the last year.
The star shared the cover image for her Amazon Original Stories essay "Take the Lead" on Instagram on Monday and with it, the news of her former diagnosis.
"We have all been handed challenges and fears in our lives that, at times, felt like too much to overcome. This past year has been especially intense for me and so many of you," she began in the post's caption. "I started writing this essay on the same day I received a positive test result for COVID-19."
Instead of feeling "driven by fear," Simpson said, she chose to "manifest a hopeful conversation with" her fans.
"I felt strong, resilient, and God- inspired through my pen teaching me as I was sharing with you ways to get to the other side of fear," she continued.
The singer did not clarify when she was diagnosed with the novel virus, whether she experienced any symptoms or if it was passed on to any of her immediate family members.
Simpson shares three children -- Maxwell, 8, Ace, 7, and Birdie, 2 -- with her husband, former football pro Eric Johnson.
It is also unclear as to whether "Take the Lead" will address her time fighting the virus.
The essay is part of the star's large deal with Amazon, which she announced in December 2020.
In another Instagram post at the time, the star revealed that she'd partnered with the company to release two essays in addition to television content, which would include "a fictionalized coming of age series about my mid-twenties" and "a new intimate unscripted docuseries with music as a key component."
According to Simpson's Instagram post on Monday, "Take the Lead" will be available on April 29, as will an audio version narrated by the star.