Mark Fremont Schlereth (/ˈʃlɛrɪθ/; born January 25, 1966) is an American former professional football player who is a television and radio sportscaster.

Schlereth played guard in the National Football League (NFL) for 12 seasons (1989–2000) with the Washington Redskins and Denver Broncos.

Growing up in Alaska, Schlereth did not receive much attention as a college football prospect; the only schools that offered him a scholarship were Idaho and Hawaii.

Erickson departed following the 1985 season, and Schlereth started at left guard on the Vandals' offensive line for new head coach Keith Gilbertson, blocking for quarterbacks Scott Linehan and John Friesz.

On January 25, 1998, Schlereth celebrated his 32nd birthday on the same day he helped the Broncos win Super Bowl XXXII, a 31–24 victory over the Green Bay Packers.

After the 13th procedure on his left knee on July 24, 2000, Denver Broncos head coach Mike Shanahan stated, "He has a great pain threshold.

His injuries are documented on Athlete 360, the sports medicine television show hosted by Schlereth's former Redskins teammate, Dr. Mark Adickes.

The truth of the matter is, after going through my 15th operation on my left knee last November, it became painfully obvious that I couldn't sign a six-year contract for $42 worth of Tupperware.

I started to realize in the last three months of free agency that there is not a lot of market for a 6 ft. 3 in, 245-pound guard that is 35 years old and beat to a pulp."

In 2024, Schlereth became a co-host alongside Craig Carton and Danny Parkins on Fox Sports 1 (FS1)'s Breakfast Ball.

[16] Originally from Anchorage Alaska, Mark told the story his rookie year of buried fish heads, known as "Stinkheads," that native Alaskans would dig up and eat if food was scarce.