Tiaina Baul "Junior" Seau Jr. (/ˈseɪ.aʊ/; SAY-ow; January 19, 1969 – May 2, 2012) was a linebacker in the National Football League (NFL). Known for his passionate playing style, he was a 10-time All-Pro, 12-time Pro Bowl selection, and named to the NFL 1990s All-Decade Team. He was elected posthumously to the Pro Football Hall of Fame in 2015.

Originally from San Diego, California, Seau played college football at the University of Southern California (USC). He was chosen by the San Diego Chargers as the fifth overall pick of the 1990 NFL Draft. Seau started for 13 seasons for the Chargers before being traded to the Miami Dolphins where he spent three years, and spent his last four seasons with the New England Patriots.

Seau retired from pro football after the 2009 season. A standout on San Diego's only Super Bowl team, he was later inducted into the Chargers Hall of Fame and the team retired his number 55. Seau committed suicide with a gunshot wound to the chest in 2012 at the age of 43. Later studies by the National Institutes of Health (NIH) concluded that Seau suffered from chronic traumatic encephalopathy (CTE), a type of chronic brain damage that has also been found in other deceased former NFL players.