SEA Seahawks

As per one of the agreed parts of the 1970 AFL–NFL merger, the NFL began planning to expand from 26 to 28 teams. In June 1972, Seattle Professional Football Inc., a group of Seattle business and community leaders, announced their intention to acquire an NFL franchise for the city of Seattle. In June 1974, the NFL gave the city an expansion franchise. That December, NFL Commissioner Pete Rozelle announced the official signing of the franchise agreement by Lloyd W. Nordstrom, representing the Nordstrom family as majority partners for the consortium.

In March 1975, John Thompson, former executive director of the NFL Management Council and a former Washington Huskies executive, was hired as the general manager of the new team. The name Seattle Seahawks ("seahawk" is another name for osprey) was selected on June 17, 1975, after a public naming contest which drew more than 20,000 entries and over 1,700 names. These include skippers, pioneers, and lumberjacks.

Thompson recruited and hired Jack Patera, a Minnesota Vikings assistant coach, to be the first head coach of the Seahawks; the hiring was announced on January 3, 1976. The expansion draft was held March 30–31, 1976, with Seattle and the Tampa Bay Buccaneers alternating picks for rounds selecting unprotected players from the other 26 teams in the league. The Seahawks were awarded the 2nd overall pick in the 1976 draft, a pick they used on defensive tackle Steve Niehaus. The team took the field for the first time on August 1, 1976, in a pre-season game against the San Francisco 49ers in the then newly opened Kingdome.

The Seahawks are the only NFL team to switch conferences twice in the post-merger era. The franchise began play in 1976 in the aforementioned NFC West but switched conferences with the Buccaneers after one season and joined the AFC West. This realignment was dictated by the league as part of the 1976 expansion plan, so that both expansion teams could play each other twice and every other NFL franchise once (the ones in their conference at the time) during their first two seasons. The Seahawks won both matchups against the Buccaneers in their first two seasons, the former of which was the Seahawks' first regular season victory.

In 1983, the Seahawks hired Chuck Knox as head coach. Finishing with a 9–7 record, the Seahawks made their first post-season appearance, defeating the Denver Broncos in the Wild Card Round, and then the Miami Dolphins, before losing in the AFC Championship to the eventual Super Bowl champion Los Angeles Raiders. The following season, the Seahawks had their best season to that point, finishing 12–4; it would remain the best win–loss record in franchise history until their 2005 season. Knox won the NFL Coach of the Year Award.

In 1988, Ken Behring and partner Ken Hofmann purchased the team for a reported $80 million. The Seahawks won their first division title in 1988, but would miss the playoffs for the following three seasons, after which Knox left the team. For most of the 1990s, the Seahawks continued to struggle. They saw three consecutive losing seasons (1992–1994) under head coach Tom Flores, including a franchise worst 2–14 season in 1992. Following the 1994 season, Flores was fired from the team and Dennis Erickson was brought in as head coach.

In 1996, Behring and Hoffman transferred the team's operations to Anaheim, California–a widely criticized move, although the team continued to play in Seattle. The team almost relocated, and was in bankruptcy for a short period. The NFL threatened Behring with fining him $500,000 a day if he did not move the team's operations back to Seattle; with this, Behring and Hoffman sold the team to Microsoft co-founder Paul Allen in 1997 for $200 million.

Erickson's tenure as head coach ended after the 1998 season; the Seahawks missed the playoffs for all four of his seasons with the team, extending their "playoff drought" to ten consecutive seasons.

In 1999, Mike Holmgren was hired as head coach. He would coach for 10 seasons. The Seahawks won their second division title, as well as a wild card berth in the playoffs, losing to the Miami Dolphins 20–17.

In 2002, the Seahawks returned to the NFC West as part of an NFL realignment plan that gave each conference four balanced divisions of four teams each. This realignment restored the AFC West to its initial post-merger roster of original AFL teams Denver, San Diego, Kansas City, and Oakland. That same year, the team opened its new home stadium, Seahawks Stadium, after spending the last two seasons at Husky Stadium after the Kingdome's implosion in 2000.

In the 2005 season, the Seahawks had their best season in franchise history (a feat that would later be matched in 2013) with a record of 13–3, which included a 42–0 rout of the Philadelphia Eagles in a Monday Night Football game. The 13–3 record earned them the number one seed in the NFC. They defeated the Washington Redskins in the Divisional Round and won the NFC Championship Game against the Carolina Panthers, but lost in Super Bowl XL against the Pittsburgh Steelers. The loss was controversial; NFL Films has Super Bowl XL at number 8 on its top ten list of games with controversial referee calls. Referee Bill Leavy later admitted that he missed calls that altered the game. Before 2005, the Seahawks had not won a playoff game since the 1984 season, a streak of 21 years (five teams had ever had a drought of twenty years at the time, with their six straight losses being tied for third-most in history). That drought was ended with a 20–10 win over the Washington Redskins in the 2005 playoffs.

In the 2006 season, the Seahawks finished 9–7 and won the NFC West. The defeated the Dallas Cowboys 21–20 in the Wild Card Round before losing to the Chicago Bears 27–24 in the Divisional Round. In the 2007 season, the Seahawks finished 10–6 and won the NFC West. The team defeated Washington in the Wild Card Round 35–14 before losing to the Green Bay Packers in the Divisional Round 42–20. The 2008 season saw the team go 4–12 and finish third in the NFC West. Holmgren departed from the team after the 2008 season, following the end of his contract. Defensive backs coach Jim L. Mora was named as Holmgren's successor. In 2009, the Seahawks finished 3rd in the NFC West with a 5–11 record. Shortly after, Mora was fired on January 8, 2010.

In the 2010 NFL season, the Seahawks made history by making it into the playoffs despite having a 7–9 record. They had the best record in a division full of teams with losing seasons (Seahawks 7–9, Rams 7–9, 49ers 6–10, Cardinals 5–11) and won the decisive season finale against the Rams (not only by overall record, but by division record, as both teams coming into the game had a 3–2 division record). In the playoffs, the Seahawks beat the defending Super Bowl XLIV champs, the New Orleans Saints, 41–36. The Seahawks made even more history during the game with Marshawn Lynch's 67-yard run, breaking 9 tackles, to clinch the victory. After the run, the fans reacted so loudly that a small earthquake (a bit above 2 on the Richter Scale) was recorded by seismic equipment around Seattle. Lynch's run would be nicknamed the "Beast Quake". The Seahawks lost to the Bears in their second game, 35–24. The 2011 season saw the team go 7–9 once again, but they were not able to get into the postseason with a third-place finish in the NFC West.

The 2012 NFL season started with doubt, as the Seahawks lost their season opener against the Arizona Cardinals. The highly touted Seattle defense gave up a go-ahead score late in the fourth quarter, and rookie quarterback Russell Wilson failed to throw the game-winning touchdown after multiple attempts in the red-zone. However, Russell Wilson and the Seahawks went 4–1 in their next five games en route to an 11–5 overall record (their first winning record since 2007). Their 2012 campaign included big wins over the Green Bay Packers, New England Patriots, and San Francisco 49ers. The Seahawks went into the playoffs as the No. 5 seed and the only team that season to go undefeated at home. In the Wild Card Round, the Seahawks overcame a 14-point deficit to defeat the Washington Redskins. This was the first time since the 1983 Divisional Round that the Seahawks won a playoff game on the road. However, in the 2012 Divisional Round, overcoming a 20-point, fourth-quarter deficit would not be enough to defeat the #1 seed Atlanta Falcons. An ill-advised timeout and a defensive breakdown late in the game cost the Seahawks their season, as they lost, 30–28. Quarterback Russell Wilson won the 2012 Pepsi MAX Rookie of the Year award.

In the 2013 NFL season, the Seahawks continued their momentum from the previous season, finishing tied with the Denver Broncos for an NFL-best regular season record of 13–3, while earning the NFC's #1 playoff seed. Their 2013 campaign included big wins over the Carolina Panthers, New Orleans Saints, and the San Francisco 49ers. Six Seahawks players were named to the Pro Bowl: Quarterback Russell Wilson, center Max Unger, running back Marshawn Lynch, cornerback Richard Sherman, free safety Earl Thomas, and strong safety Kam Chancellor. However, none of them were able to play in the Pro Bowl, as the Seahawks defeated the New Orleans Saints 23–15 and the San Francisco 49ers 23–17, in the playoffs to advance to Super Bowl XLVIII against the Denver Broncos. On February 2, 2014, the Seahawks won the franchise's only Super Bowl Championship, defeating Denver 43–8. The Seahawks' defense performance in 2013 was acclaimed as one of the best in the Super Bowl era.

The 2014 campaign saw the team lose some key pieces, including wide receiver Golden Tate to free agency and wide receiver Sidney Rice and defensive end Chris Clemons to retirement. Percy Harvin was also let go mid-season after several underachieving weeks and clashes with the rest of the locker room. Despite starting 3–3, they rallied to a 12–4 record, good enough once again for the #1 seed in the NFC Playoffs. After dispatching the Carolina Panthers handily in the Divisional Round 31–17, they faced the Green Bay Packers in the NFC Championship Game. Despite five turnovers and trailing 19–7 late in the contest, the Seahawks prevailed in overtime to reach Super Bowl XLIX against the New England Patriots, but an ill-fated interception at the 1-yard line late in the championship game stymied a comeback attempt and thwarted the Seahawks' bid to be the first repeat Super Bowl champions since the Patriots had won Super Bowls XXXVIII and XXXIX.

The Seahawks returned to the playoffs in both 2015 and 2016, but despite winning the Wild Card game in both years they failed to win either Divisional round game on the road. The 2017 iteration of the team missed the playoffs for the first time in six years, as injuries to their core players coupled with disappointing acquisitions of running back Eddie Lacy and kicker Blair Walsh failed them in a competitive NFC. The team cut ties with most of the remaining players that had been part of their meteoric rise and turnover both their Offensive and Defensive coaching staff in 2018, and an influx of young talent helped propel the team to a 10–6 record and another playoff berth that ultimately ended in a loss in the Wild Card game to the Dallas Cowboys. In October 2018, owner Paul Allen died after a prolonged fight with cancer. In 2019, the Seahawks put up their best record since their last trip to the Super Bowl at 11–5, but they still lost 3 out of their last 4 games and lost their chance to win the NFC West. A likely explanation for their sloppy finish is because many of their players were injured late in the season. After defeating the Philadelphia Eagles 17–9 in the Wild Card game, they lost to the Green Bay Packers in the Divisional round, failing another attempt at a second Super Bowl.

The 2020 season saw the Seahawks win their first five games, a franchise-best for a start to a season. Despite the Seahawks losing three of their next four games, the Seahawks finished strong, earning twelve victories for the first time since their Super Bowl season in 2014, and winning the division for the first time in four years. However, despite the 12–4 record and the division title, the Seahawks' season ended the following week against the Los Angeles Rams, who never trailed in a 30–20 victory. The Seahawks struggled and started the 2021 season 3–8. Russell Wilson had an injured finger missing 3 games and the Seahawks were shut out the first time in the Wilson era in Week 10 against the Green Bay Packers. This was their worst first half of a season since 2009, under then-head coach Jim Mora. The Seahawks were eliminated from playoff contention on December 26 in a loss to the Chicago Bears, and they finished last in their division for the first time since 1996. With wins over the Detroit Lions and the Arizona Cardinals they finished 7–10.

Following the 2021 season was an offseason of continuing change, punctuated with the trade of quarterback Russell Wilson to the team he and the Seahawks beat in Super Bowl XLVIII, the Denver Broncos, on March 6, 2022. The Broncos traded quarterback Drew Lock, tight end Noah Fant, defensive end Shelby Harris, two first round picks (for that year's draft, No. 9 overall, and 2023's), two second round picks (that year's, No. 40 overall, and 2023's) and a 2022 fifth round selection to the Seahawks for Wilson and a 2022 fourth round pick. Another hallmark franchise player from the Super Bowl-winning Seahawks, former All-Pro linebacker Bobby Wagner, was also cut by the team that same day, a move that saves them $16.6 million in cap space. The Seahawks also took on $26 million in dead money by trading Wilson; ESPN Stats & Information research revealed it to be the second-most dead money a team has ever incurred, trailing the $33.8 million the Philadelphia Eagles ate in their trade of Carson Wentz the previous year.

In the 2022 season, the Seahawks finished with a 9–8 record and made the playoffs. The team's season ended in the Wild Card round with a 41–23 loss to the San Francisco 49ers. The 2023 season saw the Seahawks finish 9–8 and miss the postseason. Carroll was fired from his head coaching position after the 2023 season. Carroll remained with the team in an unspecified advisory role.

Mike Macdonald, formerly defensive coordinator of the Baltimore Ravens, was hired as the new head coach.