The 39-year-old singer and fashion designer participated in the Blackout Tuesday social media initiative by posting a completely black photo on Instagram. It's one of the many forms of protest people have taken part in to shine a light on police brutality.
In her post, Simpson said she, too, has been reeling from the injustice.
"I have been taken to my knees in prayer time and again over these last days. I am listening to the testimonies crying out," she captioned the post.
Noting the nation's dark times, she shared how she's been able to find some hope.
"I am hearing God's anointed power in the hearts that are steadfast. I am hopeful that God will deliver the souls of the righteous who are crushed in spirit. I have resilient faith that anything hate can do, LOVE can do better," she concluded with the hashtag #BlackoutTuesday.
Jon Bon Jovi, Steve Harvey, Don Cheadle, Kevin Bacon, Mandy Moore, Tiffany Trump, Ben Affleck, Ryan Reynolds, Jamie Lee Curtis and Chelsea Handler are among the dozens of other celebrities who participated in the social media endeavor on Tuesday.
Meanwhile, several other A-listers took to the streets across America to participate in protests. Among them was Ariana Grande, who shared she had covered "miles of peaceful protesting" throughout Los Angeles.
"We were passionate, we were loud, we were loving," the hitmaker tweeted along with photos.
"Umbrella Academy" star Ellen Page shared video from a protest outside the Barclays Center in Brooklyn, N.Y. Ben Affleck was photographed walking with a "Black Lives Matter" sign alongside his new flame, actress Ana de Armas, in Los Angeles.
And some stars opened up on social media about how they were placed in handcuffs during non-violent marches. "Riverdale" actor Cole Sprouse wrote about police using zip ties to bound protesters' hands, and Jaime King sent out a series of tweets while in police custody on a van "for hours."
Fox News' Tyler McCarthy contributed to this report.