He played college football for the Miami Hurricanes, where he was a member of their 2001 BCS National Championship team and won the Jack Tatum Trophy.

Despite missing the first game of the season, the team's only loss, he helped Gulliver win the Florida Class 2A State Championship in 2000 with a 14–1 record.

He also compiled more than 100 tackles during the season and scored three touchdowns (two receiving, one rushing) in the state title game victory over Marianna High School.

During the season, Taylor was named Big East Special Teams Player of the Week for his performance against the Pittsburgh Panthers.

He intercepted two passes in Miami's impressive 28–14 win over Pittsburgh, playing a key role as the Hurricanes limited All-American receiver Larry Fitzgerald to just three receptions for 26 yards.

He placed 4th in the 100-meter at the Gatorade Invitational in Coral Gables, Florida, with a time of 10.77 seconds, behind teammates Terrell Walden, Roscoe Parrish and Travarous Bain.

[21] Taylor also had an incident that involved his early departure during the NFL's Rookie Symposium which was mandatory for every incoming player from the draft and was held over four days.

[22] On August 9, 2004, Taylor made his professional NFL debut in the Redskins' preseason-opener as part of their second unit defense against the Denver Broncos.

During the third quarter, Taylor intercepted a pass intended for Jeb Putzier and returned it for a three-yard touchdown to put Washington in the lead 10–9.

[21] He made his professional regular season debut in the Washington Redskins' season-opener against the Tampa Bay Buccaneers and assisted on one tackle in their 16–10 victory.

In Week 3, Taylor earned his first career start after surpassing Lott on the depth chart and recorded four combined tackles and deflected two passes in the Redskins' 21–18 loss to the Dallas Cowboys.

On October 18, 2004, Taylor made four solo tackles, a pass deflection, a sack, and returned his first career interception for 45-yards during a 13–10 win at the Chicago Bears.

[24] He finished his rookie season in 2004 with 76 combined tackles (60 solo), nine pass deflections, four interceptions, two forced fumbles, and a sack in 15 games and 13 starts.

On November 11, 2005, it was reported that Taylor and teammate Clinton Portis received fines from the NFL due to violating the league's uniform code during the Redskins' 17–10 home victory against the Philadelphia Eagles in Week 9.

[29] Taylor finished the 2005 season with 70 combined tackles (60 solo), a career-high ten pass deflections, two interceptions, two forced fumbles, and a sack in 15 games and 15 starts.

On January 7, 2006, Taylor started in his first career playoff game and recorded seven combined tackles and returned a fumble for a touchdown in their 17–10 victory at the Tampa Bay Buccaneers.

On October 15, 2006, Taylor collected a season-high ten combined tackles (eight solo) and deflected a pass during a 25–22 loss to the Tennessee Titans.

In Week 9, Taylor made eight combined tackles and returned a blocked 35-yard field goal attempt by Mike Vanderjagt for a 30-yard gain with less than six seconds left in the game.

A facemask on Taylor by Kyle Kosier added a 15-yard penalty and placed the Redskins in field goal range with an untimed down.

[33] He finished the 2006 season with a career-high 111 combined tackles (86 solo), six pass deflections, three forced fumbles, and an interception in 16 games and 16 starts.

[6] Even while playing on a struggling Redskins defensive unit, Taylor's impact on the field was recognized when he was named a first alternate to the NFC's 2007 Pro Bowl team.

A crushing hit by Taylor on Buffalo Bills punter Brian Moorman in the Pro Bowl created much fan and media discussion.

[38] At the time of his death, Taylor was tied for the most interceptions in the National Football Conference and second in the league with 5 despite having missed Weeks 11 and 12 with a knee injury.

[49] On November 30, four men, Venjah K. Hunte, 20; Eric Rivera Jr., 17; Jason Scott Mitchell, 19; and Charles Kendrick Lee Wardlow, 18, were arrested.

Eric Rivera Jr. was convicted of second-degree murder, manslaughter, burglary with a battery and trespassing, and he was sentenced to 57 years in prison.

The team requested that fans arrive 25 minutes before the start of the game at 12:40pm and played a four-minute remembrance video, held a moment of silence and gave attendees commemorative towels with Taylor's number on them in his honor and memory.

On July 12, the judge postponed the trial to November 5,[70] but that date was further moved back to April 5, 2013, due to a scheduling conflict with the chief prosecutor.

[73] On November 4, a jury found Eric Rivera Jr. guilty of second-degree murder and armed burglary, which could carry a life imprisonment sentence.

Taylor's former teammate and fellow safety Ryan Clark returned to the Washington Redskins in 2014 after an eight-year stint with the Pittsburgh Steelers.

[81] On October 17, 2021, the Washington franchise retired Sean Taylor's number 21 before a game against the Kansas City Chiefs with his family in attendance.