The 2021 O'Reilly Auto Parts 253 was a NASCAR Cup Series race that was held on February 21, 2021 at Daytona International Speedway in Daytona Beach, Florida.

Added as a replacement for the cancelled Auto Club 400 because of California restrictions related to the COVID-19 pandemic, the 2021 race was scheduled for 70 laps on the road course, it was the second race of the 2021 NASCAR Cup Series season. The race was lengthened from the 2020 schedule, where it was run at 65 laps of the course for 235 miles. It was classified as a race in 2021, similar to the Charlotte and Road America road course races.

At , it was the slowest Daytona race in NASCAR Cup Series history, although it was run on the road course, Christopher Bell scored his inaugural Cup Series win.

Le Mans Chicane issues During the Busch Clash, which had been held on the road course as planned in order to allow the current (sixth-generation) NASCAR Cup car to be used before the seventh-generation Cup car would have been launched in 2021 before a delay was announced because of developmental delays, track visibility issues came after a safety car situation was called on Lap 9 of the first segment of 15 laps with excessive mud and dirt at the exit of the Le Mans Chicane (the bus stop on the backstretch). The mud and dirt led to Kevin Harvick spinning early in the race, visibility issues, and later in the race, leader Martin Truex Jr. caused a safety car by crashing at the exit after overdriving the chicane and losing traction from the mud that had accumulated during the race.

A social media post by Denny Hamlin confirmed on February 16 that additional work was being done in the bus stop kerbing, with officials planning to add "sausage kerbing" (also known as "turtles") to the Le Mans Chicane as used in the chicane before pit entrance (a temporary chicane in the skid pad exiting Turn 4) to prevent drivers from short-cutting the chicane and throwing mud on the circuit. The right rumble strip is long while the left is long.

Entry list (R) denotes rookie driver. (i) denotes driver who are ineligible for series driver points.

Driver Team Manufacturer 00 Quin Houff StarCom Racing Chevrolet 1 Kurt Busch Chip Ganassi Racing Chevrolet 2 Brad Keselowski Team Penske Ford 3 Austin Dillon Richard Childress Racing Chevrolet 4 Kevin Harvick Stewart-Haas Racing Ford 5 Kyle Larson Hendrick Motorsports Chevrolet 6 Ryan Newman Roush Fenway Racing Ford 7 Corey LaJoie Spire Motorsports Chevrolet 8 Tyler Reddick Richard Childress Racing Chevrolet 9 Chase Elliott Hendrick Motorsports Chevrolet 10 Aric Almirola Stewart-Haas Racing Ford 11 Denny Hamlin Joe Gibbs Racing Toyota 12 Ryan Blaney Team Penske Ford 14 Chase Briscoe (R) Stewart-Haas Racing Ford 15 James Davison Rick Ware Racing Chevrolet 16 A. J. Allmendinger (i) Kaulig Racing Chevrolet 17 Chris Buescher Roush Fenway Racing Ford 18 Kyle Busch Joe Gibbs Racing Toyota 19 Martin Truex Jr. Joe Gibbs Racing Toyota 20 Christopher Bell Joe Gibbs Racing Toyota 21 Matt DiBenedetto Wood Brothers Racing Ford 22 Joey Logano Team Penske Ford 23 Bubba Wallace 23XI Racing Toyota 24 William Byron Hendrick Motorsports Chevrolet 34 Michael McDowell Front Row Motorsports Ford 37 Ryan Preece JTG Daugherty Racing Chevrolet 38 Anthony Alfredo (R) Front Row Motorsports Ford 41 Cole Custer Stewart-Haas Racing Ford 42 Ross Chastain Chip Ganassi Racing Chevrolet 43 Erik Jones Richard Petty Motorsports Chevrolet 47 Ricky Stenhouse Jr. JTG Daugherty Racing Chevrolet 48 Alex Bowman Hendrick Motorsports Chevrolet 51 Cody Ware (i) Petty Ware Racing Chevrolet 52 Josh Bilicki Rick Ware Racing Ford 53 Garrett Smithley (i) Rick Ware Racing Chevrolet 66 Timmy Hill (i) MBM Motorsports Toyota 77 Justin Haley (i) Spire Motorsports Chevrolet 78 Scott Heckert Live Fast Motorsports Ford 96 Ty Dillon (i) Gaunt Brothers Racing Toyota 99 Daniel Suárez Trackhouse Racing Team ChevroletOfficial entry list

Starting Lineup Chase Elliott was awarded the pole for the race. This is the first of 28 scheduled one-day races using the competition-based formula from the 2020 season that began with last year's road course race based on owner point standings (35%) and from the previous round, the car's fastest lap (15%) and finishing position (driver's for 25% and owner's for 25%; 41st position is used in the average if the driver or owner did not participate in the previous race).

Pos Driver Team Manufacturer 1 9 Chase Elliott Hendrick Motorsports Chevrolet 2 34 Michael McDowell Front Row Motorsports Ford 3 3 Austin Dillon Richard Childress Racing Chevrolet 4 11 Denny Hamlin Joe Gibbs Racing Toyota 5 4 Kevin Harvick Stewart-Haas Racing Ford 6 37 Ryan Preece JTG Daugherty Racing Chevrolet 7 7 Corey LaJoie Spire Motorsports Chevrolet 8 5 Kyle Larson Hendrick Motorsports Chevrolet 9 42 Ross Chastain Chip Ganassi Racing Chevrolet 10 23 Bubba Wallace 23XI Racing Toyota 11 22 Joey Logano Team Penske Ford 12 20 Christopher Bell Joe Gibbs Racing Toyota 13 41 Cole Custer Stewart-Haas Racing Ford 14 18 Kyle Busch Joe Gibbs Racing Toyota 15 2 Brad Keselowski Team Penske Ford 16 47 Ricky Stenhouse Jr. JTG Daugherty Racing Chevrolet 17 1 Kurt Busch Chip Ganassi Racing Chevrolet 18 14 Chase Briscoe (R) Stewart-Haas Racing Ford 19 19 Martin Truex Jr. Joe Gibbs Racing Toyota 20 77 Justin Haley (i) Spire Motorsports Chevrolet 21 51 Cody Ware (i) Petty Ware Racing Chevrolet 22 24 William Byron Hendrick Motorsports Chevrolet 23 52 Josh Bilicki Rick Ware Racing Ford 24 8 Tyler Reddick Richard Childress Racing Chevrolet 25 53 Garrett Smithley (i) Rick Ware Racing Chevrolet 26 10 Aric Almirola Stewart-Haas Racing Ford 27 12 Ryan Blaney Team Penske Ford 28 78 Scott Heckert Live Fast Motorsports Ford 29 00 Quin Houff StarCom Racing Chevrolet 30 17 Chris Buescher Roush Fenway Racing Ford 31 38 Anthony Alfredo (R) Front Row Motorsports Ford 32 21 Matt DiBenedetto Wood Brothers Racing Ford 33 6 Ryan Newman Roush Fenway Racing Ford 34 16 A. J. Allmendinger (i) Kaulig Racing Chevrolet 35 99 Daniel Suárez Trackhouse Racing Team Chevrolet 36 48 Alex Bowman Hendrick Motorsports Chevrolet 37 43 Erik Jones Richard Petty Motorsports Chevrolet 38 96 Ty Dillon (i) Gaunt Brothers Racing Toyota 39 15 James Davison Rick Ware Racing Chevrolet 40 66 Timmy Hill (i) MBM Motorsports ToyotaOfficial starting lineup

Race The seventy lap race was won by Joe Gibbs Racing driver Christopher Bell in a Toyota. A safety car period was called for rain which bunched the pack up, but the leaders changed onto dry tires rather than rain tires. Another caution period was called because Tyler Reddick's car caught fire. Bell claimed the lead when he overtook Joey Logano on the penultimate lap. It was Bell's first Cup Series victory. It was the first time since the 1950 NASCAR Grand National Series that a year's opening brace of races had maiden winners. Bell's teammate Hamlin finished in third behind Logano. Polesitter Elliott led most of the race but span after a collision with Kurt Busch and came 21st. Busch finished fourth ahead of Brad Keselowski. Both drivers gained positions by not making additional pit stops. Before this, Busch had fallen down the order after he span while leading, while Keselowski had also made mistakes. Harvick followed Keselowski, while A. J. Allmendinger took Kaulig Racing's best Cup Series result in seventh. Michael McDowell, who had won the 2021 Daytona 500 a week prior, recovered from a lap one puncture to finish eighth. Kyle Larson and Kyle Busch were both in the top five in the final twenty laps, but Larson spun into a tire barrier coming out of turn 7 and finished 30th, while Busch's team made a strategic error and was involved in a minor crash with Chris Buescher, finishing 35th.

Bell said he was "not overly shocked", but felt that "to win the first road course of the year is quite surprising". He also said that he "certainly knew we would be in contention or at least competitive today." He expressed the view that road racing "showcases talent".

The caution flag flown for rain during the last stage of the race was criticized as an "entertainment" caution, due to the surface being not being considered too wet to continue racing, as well as also altering the finish of the race preventing Elliott (who, alongside Kyle Busch, questioned the caution over the radio on NASCAR Race Hubs Radioactive segment, the show's team radio chatter highlights) from walking away easily with a win. The race had been declared a dry race at the start. Had the start been declared a wet race (teams must start on rain tires), NASCAR would not call a safety car situation if it dries, and rains again. A subsequent rule change in 2022 states if a road course race was not declared wet to start, a safety car is no longer automatically implemented when rain becomes an issue to prevent this situation. The rule is still used on ovals that can be run in the rain if the race is declared dry.

Stage ResultsStage OneLaps: 16

Pos Driver Team Manufacturer Points1 9 Chase Elliott Hendrick Motorsports Chevrolet 102 22 Joey Logano Team Penske Ford 93 11 Denny Hamlin Joe Gibbs Racing Toyota 84 2 Brad Keselowski Team Penske Ford 75 1 Kurt Busch Chip Ganassi Racing Chevrolet 66 5 Kyle Larson Hendrick Motorsports Chevrolet 57 19 Martin Truex Jr. Joe Gibbs Racing Toyota 48 3 Austin Dillon Richard Childress Racing Chevrolet 39 4 Kevin Harvick Stewart-Haas Racing Ford 210 17 Chris Buescher Roush Fenway Racing Ford 1Official stage one resultsStage TwoLaps: 18

Pos Driver Team Manufacturer Points1 11 Denny Hamlin Joe Gibbs Racing Toyota 102 1 Kurt Busch Chip Ganassi Racing Chevrolet 93 22 Joey Logano Team Penske Ford 84 20 Christopher Bell Joe Gibbs Racing Toyota 75 19 Martin Truex Jr. Joe Gibbs Racing Toyota 66 9 Chase Elliott Hendrick Motorsports Chevrolet 57 24 William Byron Hendrick Motorsports Chevrolet 48 41 Cole Custer Stewart-Haas Racing Ford 39 16 A. J. Allmendinger (i) Kaulig Racing Chevrolet 010 18 Kyle Busch Joe Gibbs Racing Toyota 1Official stage two results

Final Stage ResultsStage Three'''Laps:'' 36