He later transferred to Purdue University, where he played football for two years with the Boilermakers and was named an All-Big Ten Conference guard.

While he was initially a substitute, Gibron developed into a strong lineman on Cleveland teams that won NFL championships in 1950, 1954 and 1955 behind an offensive attack that featured quarterback Otto Graham, end Dante Lavelli and tackle Lou Groza.

Gibron was fired in 1974, and spent the following year as coach of the Chicago Winds, a team in the short-lived World Football League.

Gibron was born in Michigan City, Indiana to Lebanese immigrant parents from Zahlé,[1] and attended Elston High School.

[2][3] Gibron was the captain of his high school football team and was named an All-Northern Indiana Athletic Conference player.

[2] He played his freshman year of college football there and was captain of the team, which finished the season with a 6–1 win–loss record and won the Indiana Intercollegiate Conference championship under head coach Loren Ellis.

[2][6] Purdue had a losing record in each of those years, but Gibron was named an All-Big Ten Conference player and an honorable mention All-American.

[2][7] Gibron was selected by the Buffalo Bills in the first round of a secret draft held in 1948 by the All-America Football Conference (AAFC).

[13] Gibron, however, was sold along with halfback Rex Bumgardner and defensive tackle John Kissell to the Browns in a deal that gave Bills owner James Breuil a 25% share in the team.

[14][15] In the Browns, Gibron joined a team that had won all of the AAFC's four championships behind an offense that featured quarterback Otto Graham, fullback Marion Motley and ends Mac Speedie and Dante Lavelli.

[23] Gibron, who was unusually quick for his large size, was selected to play in the Pro Bowl, the league all-star game, after the season.

[9][24] Another championship game appearance and loss to the Lions followed in 1953, when Gibron was again named to the Pro Bowl and was selected to one sportswriter's first-team All-Pro list.

[9][27] Gibron played part of the 1956 season for the Browns, but he suffered a leg injury and was cut in November to make room on the roster for rookie Don Goss.

[46] It was initially thought that Gibron would make good on his promise to deliver a championship to Chicago; he was regarded as one of the best line coaches in the game.

[3] Running back Gale Sayers, who had anchored Chicago's offense during the mid- to late-1960s, had suffered two knee injuries and was forced to retire during training camp in 1972.

[3] Chicago had the fourth overall pick in the 1975 NFL draft, using it to select future all-time rushing leader Walter Payton.

[56] He then served as a scout for the Seattle Seahawks by head coach Chuck Knox, and was accused later in the year of spying on the Cincinnati Bengals and attempting to steal their signals.

[59] A humorous clip of Gibron singing Joy to the World on the sidelines during a 1973 game against Denver was made famous by NFL Films in Football Follies.

[61] As his coaching career was drawing to a close in 1984, Gibron's teenage son James struck and killed a woman from Largo, Florida while driving drunk.