The head coach in the NFL with the longest tenure is Mike Tomlin. and he declared his departure.

Michael Pettaway Tomlin (born March 15, 1972) is an American football coach who is the head coach for the Pittsburgh Steelers in the National Football League (NFL)

. Since joining the Steelers in 2007, he has led the team to eleven playoff runs, seven division titles, three AFC Championship Games, two Super Bowl appearances, and a title in Super Bowl XLIII.

At age 36, Tomlin became the youngest head coach to win the Super Bowl, a record which was later broken by Sean McVay in Super Bowl LVI. Tomlin holds the record for most consecutive non-losing seasons to begin a coaching career with 17 and has never had a losing season. Only Tom Landry (21) and Bill Belichick (19) have had longer such streaks at any point in their coaching careers. Upon Belichick’s departure from the New England Patriots following the 2023 season, Tomlin is the NFL’s longest-tenured active head coach.

Early life
Tomlin was born in Hampton, Virginia,[1] the younger of two sons; his brother, Eddie, is three and a half years older. Their father, Ed Tomlin, played football at Hampton Institute in the 1960s, was drafted by the Baltimore Colts, and later played for the Montreal Alouettes in the Canadian Football League. The elder Tomlin died in January 2012 from an apparent heart attack in Ocala, Florida, at the age of 63. However, Tomlin hardly knew his birth father and was raised by his mother and stepfather, Julia and Leslie Copeland, who married when Tomlin was six years old.

Tomlin graduated in 1990 from Denbigh High School in Newport News, Virginia. He graduated from the College of William and Mary with a sociology degree in 1995,[2] becoming a member of Kappa Alpha Psi fraternity. As a wide receiver, Tomlin was a second-team All-Yankee Conference selection in 1994.