2005 NCAA Division I-A football season

The 2005 NCAA Division I-A football season was the highest level of college football competition in the United States organized by the National Collegiate Athletic Association (NCAA). The regular season began on September 1, 2005 and ended on December 3, 2005. The postseason concluded on January 4, 2006 with the Rose Bowl, which served as the season's BCS National Championship Game.

The USC Trojans and the Texas Longhorns finished the regular season as the only undefeated teams in Division I-A and consequently met in the Rose Bowl to play for the national title. Texas defeated USC largely due to the performance of quarterback Vince Young, who gained 467 yards of total offense and ran for three touchdowns. The Longhorns won their first national championship since 1970, and their first consensus national title since 1969.

Rule changes

 * *After the Big Ten Conference's 2004 experiment with instant replay, its use was expanded to all but the Sun Belt and the WAC conferences in Division I-A. The rules varied between conferences (including the use of coaches' challenges similar to the NFL in the Mountain West Conference) until the NCAA standardized the rules in 2006. Replay was also permitted in bowl games and, provided the visiting team agreed to its use, in non-conference regular season games.
 * The protection for a receiver who signals a fair catch includes situations when the ball is muffed until it hits the ground.
 * Penalties for spearing or similar hits in which the tackler leads with the crown of the head are enforced regardless of the "intent" of the tackler.
 * The penalty for leaping on field goals/PATs now states it is a foul if a player lined up more than one yard behind the line of scrimmage jumps and lands on players of any team trying to block the kick. If lined up one yard or closer to the line, it is not a foul.
 * Eliminated the "legal clipping zone"; hits from behind below the knee are prohibited anywhere on the field.
 * Provided for officials a specific list of acts by players considered unsportsmanlike conduct, including the "throat slash", high stepping and diving into the end zone unchallenged among others. Spontaneous celebrations by players are allowed provided they are not prolonged, taunting, or bring attention to themselves.

Conference changes
A major conference realignment occurred prior to the 2005 season, when 18 teams in Division I-A changed conferences.

Temple was expelled from the Big East Conference while Army ended its brief affiliation with Conference USA, resulting in both schools becoming Independents.

Boston College left the Big East to become the 12th member of the Atlantic Coast Conference (ACC), allowing the league to split into two divisions and hold an annual championship game.

Cincinnati, Louisville and South Florida left Conference USA to join the Big East. Texas Christian University also left Conference USA to become the Mountain West Conference's ninth member.

Despite its losses, Conference USA added six schools to increase its membership to twelve, poaching Marshall and UCF from the Mid-American Conference and Rice, Southern Methodist, Tulsa, and UTEP from the Western Athletic Conference (WAC). Like the ACC, Conference USA split into two divisions and started a conference championship game.

The Western Athletic Conference added Idaho, New Mexico State and Utah State from the Sun Belt Conference.

The Sun Belt picked up I-AA Independents Florida Atlantic and Florida International.

Coaching changes
Steve Spurrier returned to college coaching for the first time since 2001 after a stint in the NFL, leading South Carolina to a respectable 7–5 season. Urban Meyer, after leading Utah to an undefeated season in 2004, took over at Florida (Spurrier's old school). Charlie Weis left the New England Patriots to become head coach at alma mater Notre Dame, taking the team to a BCS bowl.

Longtime head coaches Barry Alvarez of Wisconsin and Bill Snyder of Kansas State, both of whom took struggling programs to national prominence during their tenures, retired. Dan Hawkins, having helped make Boise State a powerhouse in the Western Athletic Conference, left the Broncos to coach struggling Colorado.

Regular season top 10 matchups
Rankings reflect the AP Poll. Rankings for Week 8 and beyond will list BCS Rankings first and AP Poll second. Teams that failed to be a top 10 team for one poll or the other will be noted.
 * Week 2
 * No. 2 Texas defeated No. 4 Ohio State, 25–22 (Ohio Stadium, Columbus, Ohio)
 * Week 3
 * No. 6 Florida defeated No. 5 Tennessee, 16–7 (Ben Hill Griffin Stadium, Gainesville, Florida)
 * Week 4
 * No. 10 Tennessee defeated No. 4 LSU, 30–27 OT (Tiger Stadium, Baton Rouge, Louisiana)
 * Week 6
 * No. 5 Georgia defeated No. 8 Tennessee, 27–14 (Neyland Stadium, Knoxville, Tennessee)
 * Week 7
 * No. 1 USC defeated No. 9 Notre Dame, 34–31 (Notre Dame Stadium, South Bend, Indiana)
 * Week 8
 * No. 2/2 Texas defeated No. 7/10 Texas Tech, 52–17 (Darrell K Royal–Texas Memorial Stadium, Austin, Texas)
 * Week 10
 * No. 6/5 Miami defeated No. 3/3 Virginia Tech, 27–7 (Lane Stadium, Blacksburg, Virginia)
 * Week 11
 * No. 7/5 LSU defeated No. 3/4 Alabama, 16–13 OT (Bryant-Denny Stadium, Tuscaloosa, Alabama)

BCS bowls

 * Rose Bowl: No. 2 (BCS No. 2, Big 12 Champ) Texas 41, No. 1 (BCS No. 1, Pac 10 Champ) Southern California 38
 * Fiesta Bowl: (BCS No. 4) No. 4 Ohio State 34, (At Large) No. 5 Notre Dame 20
 * Sugar Bowl: (Big East Champ) No. 11 West Virginia 38, (SEC Champ) No. 8 Georgia 35
 * Orange Bowl: (Big Ten Champ) No. 3 Penn State 26, (ACC Champ) No. 22 Florida State 23 (3 OT)

Other New Year's Day bowls

 * Cotton Bowl: No. 13 Alabama 13, No. 18 Texas Tech 10
 * Capital One Bowl: No. 21 Wisconsin 24, No. 7 Auburn 10
 * Gator Bowl: No. 12 Virginia Tech 35, No. 15 Louisville 24
 * Outback Bowl: No. 16 Florida 31, No. 25 Iowa 24

December bowl games

 * Peach Bowl: No. 10 LSU 40, No. 9 Miami (FL) 3
 * Houston Bowl: No. 14 TCU 27, Iowa State 24
 * Liberty Bowl: (C-USA Champ) Tulsa 31, Fresno State 24
 * MPC Computers Bowl: No. 19 Boston College 27, Boise State 21
 * Meineke Car Care Bowl: NC State 14, South Florida 0
 * Independence Bowl: Missouri 38, South Carolina 31
 * Sun Bowl: No. 17 UCLA 50, Northwestern 38
 * Music City Bowl: Virginia 34, Minnesota 31
 * Holiday Bowl: Oklahoma 17, No. 6 Oregon 14
 * Emerald Bowl: Utah 38, No. 24 Georgia Tech 10
 * Alamo Bowl: Nebraska 32, No. 20 Michigan 28
 * Insight Bowl: Arizona State 45, Rutgers 40
 * Champs Sports Bowl: No. 23 Clemson 19, Colorado 10
 * Motor City Bowl: Memphis 38, (MAC Champ) Akron 31
 * Hawai'i Bowl: (WAC Champ) Nevada 49, UCF 48 (OT)
 * Fort Worth Bowl: Kansas 42, Houston 13
 * Las Vegas Bowl: California 35, BYU 28
 * Poinsettia Bowl: Navy 51, Colorado State 30
 * GMAC Bowl: Toledo 45, UTEP 13
 * New Orleans Bowl: Southern Mississippi 31, (Sun Belt Champ) Arkansas State 19

Heisman Trophy
Heisman Trophy voting was primarily for three players: Reggie Bush, Matt Leinart (who won the trophy in 2004) and Vince Young. Bush won the trophy, with Young (who helped Texas win their first national championship since 1970) second in the voting:

In June 2010 the NCAA ruled that Bush had received "improper benefits", violating NCAA policy. On September 14, he announced in a statement from the New Orleans Saints that he would forfeit his 2005 Heisman Trophy. Runner-up Vince Young said that he would not accept the trophy if Bush forfeited it. On September 15, the Heisman Trust announced that the 2005 trophy would be vacated and there would be no winner for the season. Bush's Heisman win would be reinstanted on April 24, 2024, with the Heisman Trophy Trust citing "enormous" changes in college athletics, including the introduction of name, image and likeness (NIL) a few years prior.

Major award winners

 * Walter Camp Award (top player): Reggie Bush
 * Maxwell Award (top player): Vince Young, QB, Texas
 * AP Player Of the Year: Reggie Bush, RB, USC
 * Lombardi Award (top lineman/linebacker): A. J. Hawk, Ohio State
 * John Mackey Award (tight end): Marcedes Lewis, UCLA
 * Doak Walker Award (running back)
 * Chuck Bednarik Award (defensive player): Paul Posluszny, LB, Penn State
 * Outland Trophy (interior lineman): Greg Eslinger, C, Minnesota
 * Dave Rimington Trophy (center): Greg Eslinger, Minnesota
 * Davey O'Brien Award (quarterback): Vince Young, QB, Texas
 * Johnny Unitas Award (senior quarterback): Matt Leinart, USC
 * Fred Biletnikoff Award (wide receiver): Mike Hass, Oregon State
 * Jim Thorpe Award (defensive back): Michael Huff, Texas
 * Lou Groza Award (placekicker): Alexis Serna, Oregon State
 * Ray Guy Award (punter): Ryan Plackemeier, Wake Forest
 * The Home Depot Coach of the Year Award: Joe Paterno, Penn State
 * Paul "Bear" Bryant Award (head coach): Mack Brown, Texas
 * Broyles Award (assistant coach): Greg Davis, Texas

Highest-scoring team
Texas scored the most points (652).