Mark Shouldice known as Mark Dice, is an American YouTuber, right-wing conservative political commentator, author, and activist.

Dice is the founder of a San Diegan Christian activist group called "The Resistance", described as being "known for its hardline stance on morality". In late 2004, Dice published the website TheResistanceManifesto.com under the pseudonym John Conner. The Village Voice wrote that his pen-name was "presumably" taken from the 1984 sci-fi film The Terminator whose fictional protagonist was future Resistance leader John Connor. A year later, Dice self-published his website writings in book form as The Resistance Manifesto under the John Conner name; an updated 2008 version of the book credited Mark Dice as the author.
In 2008, in response to Starbucks' reintroduction of its original logo (featuring a topless siren), Dice led his group and its 3,000 members in boycotting the coffee chain: "The Starbucks logo has a naked woman on it with her legs spread like a prostitute […] It's extremely poor taste, and the company might as well call themselves Slutbucks." Starbucks had more than 6,000 locations in 2008.

In November 2019, KUSI-TV averaged Dice's daily videos as having 250,000 views and enumerated his YouTube subscribers at "more than 1.5 million".
As of February 2024, Dice had almost 700,000 X followers and almost 2 million YouTube subscribers.

Dice is a member of the Republican Party, although it’s unclear when he registered as a Republican. As of July 2019, he resided in Pacific Beach, San Diego.