The Seattle Seahawks' main rivals are primarily divisional opponents and a few key teams they have had intense competitive histories with. Their biggest and most heated rivals are:

• San Francisco 49ers: This is considered the Seahawks' biggest rivalry. It intensified from 2011 to 2014 when both teams were top NFC contenders. The rivalry includes playoff games and strong competition between coaches and players.

• Los Angeles Rams: The rivalry began when the Seahawks moved to the NFC West in 2002. It has been marked by playoff clashes, especially during the Seahawks' Legion of Boom era and the Rams' recent success including their 2022 Super Bowl win.

• Arizona Cardinals: Another NFC West divisional rival with a competitive and sometimes bitter rivalry especially in the mid-to-late 2010s. The presence of Bruce Arians as Cardinals coach and playoff battles fueled the rivalry.

• Green Bay Packers: Intense playoff meetings have created a rivalry despite not being divisional opponents. Key moments include memorable playoff games and dramatic comebacks.

• Denver Broncos: Historic rivals from the AFC West days, now an inter-conference rivalry with memorable playoff meetings including the Seahawks' Super Bowl XLVIII victory over the Broncos.

Other notable mentions include the Las Vegas Raiders (former AFC West rival), and some conferences and playoff rivalries with teams like the Pittsburgh Steelers and New England Patriots in previous years, though less intense currently.

In summary, the Seahawks' top rivals are the San Francisco 49ers, Los Angeles Rams, Arizona Cardinals, Green Bay Packers, and Denver Broncos, with the 49ers being the biggest and most hated rival. These rivalries are fueled by divisional battles, playoff clashes, and historic competition.