The Seahawks are the only NFL franchise based in the Pacific Northwest region of North America, and thus attract support from a wide geographical area, including Oregon, Montana, Idaho, and Alaska, as well as Canadian fans in British Columbia and Alberta.
Seahawks fans have been referred to collectively as the "12th Man", "12th Fan", or "12s". The Seahawks' fans have twice set the Guinness World Record for the loudest crowd noise at a sporting event, first on September 15, 2013, registering 136.6 dB during a game against the San Francisco 49ers and again on December 2, 2013, during a Monday Night Football game against the New Orleans Saints, with a then record-setting 137.6 dB.
Over the years the Seahawks have had some notable players on the team, including Steve Largent, Dave Brown, Jim Zorn, Dave Krieg, John Randle, Kenny Easley, Curt Warner, Joe Nash, Brian Blades, Cortez Kennedy, Joey Galloway, Walter Jones, Steve Hutchinson, Shaun Alexander, Matt Hasselbeck and Marcus Trufant. Largent, Kennedy, and Moon have been inducted into the Pro Football Hall of Fame, as was Jones in 2014. Easley, Jones, Kennedy, Krieg, Largent, Warner, and Zorn have been inducted into the Seahawks Ring of Honor, along with cornerback Dave Brown and defensive end Jacob Green.
The Seahawks have won nine division titles and three conference championships. They are the only team to have played in both the AFC and NFC Championship Games. They have appeared in three Super Bowls, including Super Bowl XLVIII, where they defeated the Denver Broncos 43–8 to win their first NFL title. However, the Seahawks went on to lose Super Bowl XLIX to the New England Patriots, 28–24. They are also the first, and to date only, post-merger expansion team in NFL history to advance to play in consecutive Super Bowls.