Coryatt attended Baytown Lee High School in Baytown, Texas. He accepted a football scholarship to attend Texas A&M University.
At Texas A&M, Coryatt became the centerpiece of outstanding Aggies defensive units (nicknamed "Wrecking Crew"), along with players like Mark Wheeler, Marcus Buckley, Kevin Smith, Derrick Frazier, and Patrick Bates.
In his junior season, he gained fame in a nationally televised game in 1991 by knocking out Texas Christian University wide receiver Kyle McPherson with a ferocious hit on a pass over the middle, breaking McPherson's jaw in three places. ESPN named it the "Hit of the Year". In his junior season, the Aggie defense ranked first in the nation. He was selected second team All-American and all-SWC, and also was named the SWC Defensive Player of the Year. Coryatt elected to forgo his senior season and declare for the NFL Draft.
In 2009, he was inducted into the Texas A&M Athletic Hall of Fame.
Entering the 1992 NFL Draft, the Indianapolis Colts owned the first two overall draft picks. After selecting defensive tackle Steve Emtman, the team chose Coryatt who was projected as the No. 1 linebacker in a draft that also included Robert Jones and Levon Kirkland. It was the highest draft position for a Texas A&M player since John David Crow in 1958.
As a rookie, he became the starter at inside linebacker in the team's 3-4 defense, recording 54 tackles, 2 sacks and 2 forced fumbles, while playing in just seven games, after being placed on the injured reserve list with a broken left wrist he suffered against the Miami Dolphins. The next year the team changed to a 4-3 defense and he was moved to middle linebacker, where he registered 150 tackles.
In 1994, Vince Tobin was hired as the new defensive coordinator and proceeded to move Coryatt to right outside linebacker, where he tallied 141 tackles. The next year, he recorded 163 tackles (86 solo), 2.5 sacks, 3 fumble recoveries and his first career interception, while helping the team reach the AFC Championship Game. He became a restricted free agent following the 1995 season and was signed to a $17.5 million offer sheet by the Jacksonville Jaguars, which the Colts ended up matching, ensuring he would remain with the team.
He played just eight games in 1996, after tearing 20 percent of his left pectoral muscle and later in the season tearing his right pectoral muscle off the bone. The next year, he was limited with an injured left shoulder.
He was waived injured on August 31, 1998, and underwent reconstructive surgery on his left shoulder on September 30.
After being out of football for a year, the Dallas Cowboys gambled that he could return from his injuries and signed him on April 17, 1999. He was expected to be the starter at strongside linebacker, but was slowed down by an Achilles injury suffered during a June minicamp. After not being able to overcome his injuries, he initially announced his retirement on September 14, but tried again to come back in December and played in 4 games (one start).
Coryatt played in 82 games over a seven-year stretch in the NFL and although he was a solid contributor, injuries didn't allow him to live up to the stardom that was expected of him by virtue of his high draft status.