Schottenheimer was born September 23, 1943 in the Pittsburgh suburb of Canonsburg, Pennsylvania. His athletic talent became evident as a student at Ft. Cherry High School in nearby McDonald, Pennsylvania where he became a star athlete in football and basketball. He attended the University of Pittsburgh earning a degree in English and played linebacker for the Panthers.

After college, Schottenheimer was selected in the fourth round of the 1965 NFL Draft by the Baltimore Colts and in the seventh round of the 1965 American Football League draft by the Buffalo Bills. He signed with the Bills and spent the next three seasons with Buffalo, including the 1965 AFL Championship season. In 1969, he joined the Boston Patriots and spent the next two seasons with the Pats. He was traded to the Pittsburgh Steelers in 1971 but was traded again to the Colts before the beginning of the 1971 season. He retired from football in 1971 and spent the next several years working in the real estate industry. Schottenheimer credits his NFL career as being his inspiration for coaching.

His professional coaching career began in 1974 when he became linebackers coach for the Portland Storm of the World Football League. In 1975 he was hired as a linebackers coach for the New York Giants and in 1977 became defensive coordinator. Schottenheimer spent the 1978 and 1979 as the linebackers coach for the Detroit Lions. In 1980, he was hired as the defensive coordinator for the Cleveland Browns. Schottenheimer became Cleveland's head coach midway through the 1984 season, replacing fired head coach Sam Rutigliano.

Schottenheimer would remain with the Browns until 1988, amassing 44-27 (.620) regular-season record and a 2-4 (.333) mark in the playoffs, including four playoff appearances, three AFC Central Division titles, and two trips to the AFC Championship Game.

Schottenheimer spent 10 seasons as head coach of the Kansas City Chiefs from 1989 to 1998 recording an impressive 101-58-1 regular season record (.634) including seven playoff appearances and three division titles. After a disappointing 7-9 season in 1998, Schotterheimer resigned as Chiefs head coach on January 11, 1999.

After working as a football analyst for ESPN from 1999 to 2000, Marty was hired as head coach of the Washington Redskins. In a controversial move, Daniel Snyder, the owner of the Redskins, fired Schottenheimer on January 13, 2002 after just one season (8-8, .500), to make room for former University of Florida head coach Steve Spurrier. Spurrier's own tenure with the Redskins was unsuccessful and he resigned in December 2003 after posting two losing seasons and looking out of his element.

The San Diego Chargers hired Schottenheimer as their 13th head coach on January 29, 2002. Schottenheimer has posted a 33-31 record (.500) with the Chargers including a playoff appearance, his 12th as a head coach, in 2004. In the wildcard round game played on January 8, 2005, the Chargers were upset by the underdog New York Jets 20-17 after going into sudden death overtime.

On January 14, 2005, the Chargers announced that they had signed Schottenheimer to a two year contract extension running through the end of the 2007 season.

Schottenheimer has led his teams to the playoffs 12 times, more than any other active NFL coach. He is tied for third (along with Chuck Noll and Bud Grant) in most playoff appearances by an NFL head coach since 1960. Only Don Shula (19) and Tom Landry (18) have led their teams to more playoff appearances.

However, Schottenheimer's success in the regular season combined with his disappointing record in post-season play has led some pundits to label him as a coach who "can't win in the playoffs." The January 8, 2005 loss to the Jets brought his career playoff record to 5-12 (.294). In his 12 post-season appearances, Schottenheimer's teams have failed to win a playoff game eight times and a Schottenheimer coached team has not won a playoff game since the 1993 season.

Schottenheimer failed to take his team to the playoffs in the 2005 NFL season.