Prior to his NFL career, Young was a member of the Los Angeles Express in the United States Football League (USFL) for two seasons.

He played college football for the BYU Cougars, setting school and NCAA records en route to being runner-up for the 1983 Heisman Trophy.

Young was named the AP's NFL Most Valuable Player in 1992 and 1994, and was the MVP of Super Bowl XXIX where he led the 49ers to a victory over the San Diego Chargers with a record six touchdown passes.

However, Young worked hard to improve his passing skills and eventually succeeded record-setting Jim McMahon as BYU's starting quarterback.

Young capped his college career by scoring the game-winning touchdown on a pass from the halfback in BYU's 21–17 victory over Missouri in the 1983 Holiday Bowl.

At the time Young left college the USFL was proving a serious challenge to the established NFL, and he had a choice to be a top pick in either league.

Klosterman also told Young that Hall of Fame coach Sid Gillman, who had been hired as a consultant, would tutor him on how to be a pro quarterback.

Despite a roster which included such future NFL players as Jojo Townsell, Mel Gray, and Kevin Nelson, and making the Western Conference title game in Young's first season, the Express were never able to create a sustaining fan base in Los Angeles.

Near the end of the 1984 season, Express owner J. William Oldenburg was forced to give up control of the team after multiple reports revealed he had misrepresented his net worth.

Houston Gamblers minority owner Jay Roulier was cleared to buy the team, only to be pushed out shortly before the 1985 preseason when it emerged that he too had lied about his finances.

Before the Express' final home game — which had been moved to Los Angeles Pierce College in the San Fernando Valley — the bus driver refused to leave unless he was paid up front, in cash.

[b] Included in that negotiation was a payment of $1.4 million for the balance of the 10-year annuity (less money paid out against it), and salaries for the remaining two years of the deal "in excess of $450,000" annually according the USFL Commissioner then overseeing the LA Express (which had fallen into receivership).

49ers coach Bill Walsh was impressed by Young's natural abilities, and believed his lackluster numbers were primarily due to the lack of talent around him in Tampa Bay.

While Montana won the NFL MVP award and led the team to a victory in Super Bowl XXIV, Young still had a good season, completing 69% of his passes for 1,001 yards, eight touchdowns, and only three interceptions.

Following an injury to Montana's elbow in the 1990 NFC Championship Game, which forced him to miss the entire 1991 season, Young got his chance to lead the 49ers, but got off to a rough start.

In the ninth game of the season, after throwing a franchise-record 97-yard touchdown pass to Taylor, Young suffered a knee injury and was replaced by backup quarterback Steve Bono.

After a loss in that game and the next, Bono led the 49ers to five consecutive victories, playing so well that coach George Seifert decided to keep him in the starting lineup after Young had recovered.

San Francisco came close to trading Young to the Los Angeles Raiders, but no deal was finalized and it turned out that Montana would not recover in time to start in the opening game.

On the fifth play of the opening game at the New York Giants, he suffered a concussion and was replaced by Bono, who threw two touchdown passes while leading the 49ers to a 31–14 victory.

The following week, the 49ers lost 34–31 to the Buffalo Bills, despite a career-high 449 passing yards and three touchdowns from Young, in a game that for the first time in NFL history had zero punts from either team.

Many credit his turnaround to the mentoring of the 49ers' new offensive coordinator Mike Shanahan, who worked with Young on combining his running skill with on-the-move passing decisions.

After several key free agent signings (including All-Pro cornerback Deion Sanders) and NFL draft selections, the 49ers looked to win their first Super Bowl since 1989.

After an easy 44–15 victory over the Chicago Bears in the Divisional Round,[22] the 49ers jumped out to a 31–14 halftime lead over the Dallas Cowboys in the NFC Championship Game, holding on to win 38–28.

Additionally, Young broke Joe Montana's single-season mark with a then-record 112.8 passer rating, and also once again demonstrated his great scrambling ability, accumulating another 289 yards and seven touchdowns on the ground.

Although Young was offered a job as the starting quarterback of the Denver Broncos (where his former offensive coordinator, Mike Shanahan, was the head coach), he retired because of his repeated concussions.

[30][31] In a 2013 Frontline interview, Young said that, partially based upon their own experiences, he and many retired players are increasingly concerned about repeated concussions and subconcussive hits.

Young's 4,239 rushing yards are the sixth most ever gained by a quarterback, behind Michael Vick, Cam Newton, Russell Wilson, Lamar Jackson, and Randall Cunningham.

This non-profit organization plans expeditions to African and South American countries to provide life skills mentoring with sustainable solutions in education, enterprise, health and simple technology.

[51][52] Young also serves as the national spokesman for an organization founded by former Save Darfur Coalition executive director and founder, David Rubenstein.

[53] Young began his affiliation with the organization in 2009, when he became the honorary league commissioner for their charitable dodgeball tournaments held on college campuses nationwide.