Ron Dayne (born March 14, 1978 in Berlin, New Jersey) is an American football player, playing running back for the Denver Broncos of the NFL.

Dayne was a star running back throughout high school (Overbrook High School in Pine Hill, New Jersey) and was recruited by many colleges around the nation. One of the reasons for this attention was Dayne's athleticism. Out of high school, he weighed 266 pounds and ran a 4.6. Eventually Barry Alvarez convinced Dayne to come to the University of Wisconsin.

Despite his virtually monotonous attitude and demeanor, Dayne is usually considered one of the greatest backs in Wisconsin and NCAA football history. Known as "The Great Dayne" throughout college, Dayne was the starting running back all four years at Wisconsin. Never a flashy or boisterous player, Dayne was a workman-like back. Over his four seasons he broke the NCAA Division I-A rushing record for total yards in a career. He broke this record in the final game of the 1999 season against Iowa. Dayne ended his collegiate career with a total of 6,397 total yards, eclipsing the record of 6,279 total yards previously held by Ricky Williams of Texas.

Dayne saved some his best performances for the four bowl games to which he led Wisconsin. He rushed for 246 to lead the Badgers to a 38-10 victory in the 1996 Copper Bowl against Utah, garnering MVP honors. Dayne only gained 36 yards in the 1998 Outback Bowl loss against Georgia the next season, but bounced back the next two seasons with 246 yards and 200 yards, respectively, in leading the Badgers to back-to-back Rose Bowl victories in 1999 and 2000 over UCLA and Stanford. Dayne won MVP honors in both Rose Bowls, becoming one of only four players to win two Rose Bowl MVPs (Washington's Bob Schloredt, Southern California's Charles White, and Texas' Vince Young are the others).

Dayne won the Heisman Trophy in 1999 over Joe Hamilton of Georgia Tech, and won numerous other awards throughout college, including Big Ten Conference player of the year in 2000 and All-American placement in 1996, 1998 and 1999. His No. 33 jersey was retired at Wisconsin following the 1999 season, and his name is one of two displayed on the Camp Randall Stadium façade (the name of Wisconsin's other Heisman winner, #35 Alan Ameche, is the other).

Dayne currently holds the NCAA record for regular season rushing yards in a career, with 6,397. Bowl games included, he amassed 7,125 yards, becoming the first player in NCAA history to total over 7,000 rushing yards. He shares the record for most 200-yard rushing games with Ricky Williams and Marcus Allen, with twelve. He also holds the Big Ten Conference rushing and total touchdowns record, with 71, and is one of five players in NCAA history to rush for over a thousand yards in each of his four seasons.

Dayne was selected with the 11th pick of the 2000 NFL Draft by the New York Giants. Dayne's first season was filled with promise as he teamed up with Tiki Barber in the backfield to create the tandem known as "Thunder and Lightning," due to the combination of Dayne's power and Barber's speed. This Giants team went on to appear in Super Bowl XXXV. Over the next few years, Dayne's carries slowly diminished, with head coach Jim Fassel growing increasingly upset with Dayne's lack of commitment to lose weight. Fassel also did not like Dayne's initial running style, that of a halfback, and instead tried to make him a goal line back. After Fassel was fired, Dayne received a second chance under new head coach Tom Coughlin and shed 40 lbs. Despite having a good 2004 preseason, Dayne was once again sidelined by Coughlin for unknown reasons. The Giants elected not to re-sign Dayne, and he later signed a one-year deal with the Denver Broncos for the 2005 season where he showed signs of rejuvenation on Thanksgiving as he carved up the Dallas Cowboys defense for 98 yards and a touchdown. He was resigned in the 2006 offseason, and will probably see a bigger workload with the departure of Mike Anderson leaving him the 2nd string back to Tatum Bell.