Block competed in the World Rally Championship and was named Rally America Rookie of the Year in 2005.
"It's with our deepest regrets that we can confirm that Ken Block passed away in a snowmobile accident today," Block's team Hoonigan Racing said in an Instagram post.
"Ken was a visionary, a pioneer and an icon. And most importantly, a father and husband. He will be incredibly missed."
Californian-born Block was a successful businessman, having co-founded the sportswear company DC Shoes before shifting his focus to Hoonigan Industries, a clothing brand for auto enthusiasts.
Block was also a YouTube star known for posting daring stunts behind the wheel.
He was introduced to a mainstream British television audience in 2016 when he appeared in an episode of BBC's Top Gear driving around London with actor and host Matt LeBlanc.
Block finished second overall in Rally America three times - in 2006, 2008 and 2013 - and competed in the World Rally Championship between 2007 and 2018.
"The #WRC family extends its sympathies to the family and friends of motorsport icon Ken Block," the WRC-FIA World Rally Championship posted on its official Twitter account.
Block died near Woodland, Utah with Sheriff's Office in Wasatch County saying he was riding on a steep slope when the snowmobile upended and landed on top of him.
"He was pronounced deceased at the scene from injuries sustained in the accident," they said in a statement.
The Sheriff's Office added that Block was riding in a group but was alone when the accident occurred.