2021 IndyCar Series (Johnsonverse)

The 2021 NTT IndyCar Series is the 26th season of the IndyCar Series and the 110th official championship season of American open wheel racing. The premier event will be the 2021 Indianapolis 500. It is the third year under Johnson management after they took over in 2019. Scott Dixon is set to enter his 21st season competing for a National Championship as the defending champion.

Driver changes

 * Five-time NASCAR Panasonic Cup Series champion Jimmie Johnson will partner with Chip Ganassi Racing to finalize sponsorship on a program to run all of IndyCar's road/street courses in 2021–2022. On October 24, 2020, the car number and primary sponsor for Johnson's car were announced, respectively the No. 48 (Johnson's long-time NASCAR number, with Hendrick Motorsports, and a number Ganassi had previously fielded in the Xfinity Series) and Carvana.
 * A. J. Foyt Enterprises signed Sébastien Bourdais to drive the No. 14 entry full-time in the 2021 season. Bourdais would also drive the No. 14 for the final three races of 2020.
 * Arrow McLaren SP announced that Oliver Askew, who had driven the No. 7 car in 2020, would not return to the team for the 2021 season. Felix Rosenqvist will move from Chip Ganassi Racing to replace Askew.
 * Team Penske announced that three-time Supercars champion Scott McLaughlin would race full-time for the team in IndyCar in 2021.
 * Chip Ganassi Racing signed Álex Palou to drive the No. 10 full-time in the 2021 season.
 * After competing in three races in 2020 with both Team Penske and Arrow McLaren SP, Hélio Castroneves will contest a six-race schedule in 2021 with Meyer Shank Racing.
 * Chip Ganassi Racing re-signed Tony Kanaan to a two-year contract to contest the oval events, in complement to Jimmie Johnson's road & street course schedule in the No. 48 entry. Kanaan previously drove for the team between 2014 and 2017.
 * Colton Herta will switch from the No. 88 Harding Steinbrenner-backed car to the No. 26, sponsored by Gainbridge.
 * Arrow McLaren SP announced that two-time Indianapolis 500 winner Juan Pablo Montoya will drive their third entry in the Indianapolis 500. This will be Montoya's first Indianapolis 500 appearance since 2017. Montoya will also drive the IndyGP.
 * Paretta Autosport, a new team run by former Dodge/SRT Motorsports director Beth Paretta, announced that Simona de Silvestro will drive an Eagle-engineered Oldsmobile in the Indianapolis 500. This will be de Silvestro's first IndyCar and Indianapolis 500 appearance since 2015, as well as Eagle's first appearance in American open-wheel championship racing since the 1999 CART season.
 * James Hinchcliffe will re-join Andretti Autosport full-time in the No. 29 after competing in 6 races for the team in the 2020 season.
 * Dale Coyne Racing with Vasser-Sullivan signed Ed Jones for the 2021 season. This will be Jones' second stint with Dale Coyne Racing, having driven for them in the 2017 season.
 * Dale Coyne Racing with Rick Ware Racing announced that Romain Grosjean would be racing for the team, driving the No. 51 entry on road and street circuits, after 10 seasons in Formula One. Pietro Fittipaldi will drive the No. 51 on the ovals. Fittipaldi will return to the IndyCar Series for the first time since 2018.
 * Santino Ferrucci will drive for Rahal Letterman Lanigan Racing in the Indianapolis 500. Ferrucci previously drove for Dale Coyne Racing from 2018–2020.
 * J. R. Hildebrand signed to drive for A. J. Foyt Enterprises for the Indianapolis 500 running a tribute livery for the 60th anniversary of A. J. Foyt's first win in the race.
 * Stefan Wilson signed to drive for Andretti Autosport for the Indianapolis 500. It would be Wilson's first IndyCar start since the 2018 Indianapolis 500.

Team changes

 * On October 28, 2020, it was announced that DragonSpeed, who competed on a part-time basis in the previous 2 seasons, will be leaving the IndyCar Series and they have sold their Panoz DP19 chassis to Meyer Shank Racing, who are fielding a second car for the 2021 season.
 * Team Penske ended their partnership with Supercars team Dick Johnson Racing (with whom McLaughlin won his three titles) to make room for another IndyCar entry and thus returned to competing with four cars for the first time since 2017.
 * Chip Ganassi Racing also returned to a regular four-car team for the first time since 2017.
 * Dale Coyne Racing announced a partnership with Rick Ware Racing (who field full- and part-time entries in numerous other series including the NASCAR Cup and Asian Le Mans Series) for the full season, changing the number of the team's second entry from No. 19 to No. 51.
 * On February 18, 2021, Andretti Autosport mentioned that James Hinchcliffe's No. 29 entry would compete under the banner of "Andretti Steinbrenner Autosport", with one of the partners from the former Andretti Harding Steinbrenner Autosport entry, George Steinbrenner IV, returning as a partner.
 * Top Gun Racing is set to make their IndyCar debut at the Indianapolis 500 with R. C. Enerson driving a Stohr-engineered Chevrolet. Top Gun Racing had originally planned to enter the 2020 Indianapolis 500, but these plans were put on hold because the race was held behind closed doors.

Schedule
On October 1, 2020, a seventeen-race calendar was announced.