Born in the same place he would later coach, the childhood fan Seifert was raised in San Francisco, ushering at 49ers home games while in high school. Seifert attended the University of Utah, playing guard and linebacker for the Utes. He served as graduate assistant for a year before being hired as head coach of Westminster College in Salt Lake City at age 25, where he led the Parsons to a 3-3 record.
As a 49er assistant, his defenses finished in the top ten in fewest points allowed in each of his six seasons in that capacity: fourth in 1983, first in 1984, second in 1985, third in 1986 and 1987, and eighth in 1988. His final two defenses, 1987 and 1988, finished first and third in fewest yards allowed, respectively. On his 49th birthday, the 49ers won the Super Bowl in 1989.
In 1989, he was elevated to head coach. He is one of only 13 NFL head coaches with more than one Super Bowl victory, winning in both the 1989 and 1994 seasons with the San Francisco 49ers. In Super Bowl XXIV he became the first rookie head coach to win the Super Bowl since Don McCafferty coached the Baltimore Colts to victory in Super Bowl V. In all, Seifert coached on five Super Bowl champion teams with the 49ers, being 1 of only 17 men to have won 5 or more championships. Seifert was forced to resign in 1996.
After two years out of the game, he was tapped by the Carolina Panthers as head coach. He was also de facto general manager as well; the Panthers hadn't had a general manager since Bill Polian's departure in 1997. During his first training camp with the Panthers, he told his players that they shouldn't act like wildebeests. He explained that wildebeests usually give up when caught by a lion. "Don't be that wildebeest," he said. "Don't give up."
In his first season, Seifert led the Panthers to an 8-8 record, a four-game improvement from 1998. The most notable play of that year came when quarterback Steve Beuerlein scored a game-winning touchdown on a fourth-and-five quarterback draw with five seconds left in overtime to defeat the Green Bay Packers. They went into the final day of the regular season in contention for a playoff berth. However, their victory margin over the New Orleans Saints needed to be 18 points greater than the Packers' margin over the Arizona Cardinals in order to have a chance to make the playoffs. While the Panthers routed the Saints 45-13, the Packers beat the Cardinals 49-24, leaving the Packers ahead on point differential and eliminating the Panthers.
The Panthers were competitive for most of 2000 as well, but needed to win their season finale against the Oakland Raiders to finish at .500. However, the Raiders drilled them 52-9, still one of the most lopsided losses in franchise history. Despite this, things appeared to be looking up for the Panthers in 2001. Seifert presided over an draft that netted the Panthers Steve Smith and Kris Jenkins, who would go on to be among the cornerstones of the franchise. Behind rookie quarterback Chris Weinke, they raced past the Minnesota Vikings 24-13. However, they wouldn't win another game all season and would finish 1-15--easily the worst record in franchise history. The 15 consecutive losses would be an NFL record for futility until the 2008 Detroit Lions went 0-16. Their final two games were played before what are still the two smallest crowds in franchise history (in terms of turnstile count)--including a 38-6 rout at the hands of the New England Patriots that drew only 21,000 people. Seifert was fired the next morning. To date, he is the only Panthers coach to have never had a winning season or coached a playoff game.