[1] Will Power of Team Penske entered the season as the reigning drivers' champion, having won the title at the final round in Laguna Seca by 16 points over his teammate Josef Newgarden.

Defending Indianapolis 500 winner Marcus Ericsson entered 2023 in a contract year for Chip Ganassi Racing.

[4][5] On December 8, 2022, the CW Network announced a reality documentary series titled 100 Days to Indy,[6] which would premiere on April 27, 2023.

[5] In February 2023, it was reported by Marshall Pruett of Racer.com that the annual Leader's Circle contracts earned by entries which compete in the full season would be reduced by $150,000 each to a value of $910,000.

[10] On February 2, 2023, the championship's sanctioning body announced that the Indianapolis 500 would no longer be a double points-paying race, ending a rule that was first established in 2014.

On July 12, 2022, Chip Ganassi Racing sent a press release saying that they had extended the contract of Álex Palou for the 2023 IndyCar season by exercising the option they held on his deal.

[67] On July 27, 2022, Chip Ganassi Racing confirmed they had filed a civil lawsuit against Palou in Marion County, Indiana.

[68] On September 14, 2022, it was announced that an agreement had been reached by all parties that would see Palou continue with Chip Ganassi for the 2023 season, and McLaren subsequently confirmed Felix Rosenqvist would be returning to AMSP.

The pitstops of the alternate tire runners left Penske's Scott McLaughlin in the lead, before he also came in and had a battle with Grosjean that was stopped by a caution caused by ECR's Conor Daly.

This time it ended in tears, though, when McLaughlin locked up his cold tires into turn one, sending both cars into the wall and promoting McLaren's Pato O'Ward into the lead.

Newgarden took the lead on lap 242, before multiple close battles were halted when Grosjean's fight with DCR's David Malukas sent the Frenchman into the wall.

Ericsson completed the podium and reclaimed the championship lead, 15 points ahead of O'Ward, who finished down in 17th after his tussle with Dixon.

[98] Round four was held at Barber Motorsports Park, and Grosjean took pole position, while O'Ward took second from Palou at the start.

McLaughlin then benefitted from Sting Ray Robb parking his DCR car with an issue, as he was able to stop before the pits were closed.

He and ECR's Rinus VeeKay controlled the early stages of the race, before the two McLarens of O'Ward and Rosenqvist took the first two spots.

Two more cautions did not trouble Palou, while Power was clipped by Dixon, initially dropping him back, but he was able to come through again to finish second.

[103] Herta started the Grand Prix at Road America on pole position and maintained his lead ahead of Palou and O'Ward, before the latter dropped down and promoted CGR's Marcus Armstrong to third.

[104] At the Honda Indy 200, Herta bounced back from his demise to take another pole position, this time ahead of Rahal.

Palou, who had started fourth, overtook Kirkwood for third and then overcut both leaders, while Rahal suffered a pitstop issue that dropped out of contention and allowed Dixon into third place.

During the second round of stops, Herta was then hit with a pit lane speeding penalty that dropped him down to eleventh place.

Championship leader Palou finished eighth, his lowest result of the season, and saw his standings lead shrink to 98 points ahead of newly second-placed Newgarden.

A late caution set up a three-lap shootout where Rosenqvist was jumped by Power, causing him to slip down the order and gifting Palou third place.

[108] McLaughlin took pole for the Music City Grand Prix and led O'Ward and Herta in the opening stages, before a sudden rear wing collapse for Malukas brought out the first caution.

A late caution for Linus Lundqvist, making his debut at MSR as an injury substitute for Simon Pagenaud, and a subsequent red flag after the restart helped Palou to meet his fuel saving goals.

[109] Next up was the Gallagher Grand Prix, that began with Rahal on pole position and drama on the first lap: Andretti's Devlin DeFrancesco made a brilliant move from fifth to the lead at the start, before championship chasers Newgarden and Dixon crashed and spun respectively at turn seven.

A round of stops did not change the order of the leaders, but Lundgaard in third was fastest at this stage, taking second and beginning to put pressure on Rahal.

This left Dixon without any opposition to take another remarkable win ahead of O'Ward, while Malukas took his second career podium, both coming at WWTR.

With the final race, Chevrolet secured the Manufacturers' Cup, while Armstrong took eighth place to win Rookie of the Year honors.

Crucial moments like his collision with VeeKay during a pit stop at the Indy 500, where he managed to salvage fourth place afterwards, further contributed to his dominant title.

Last years' second placed driver Newgarden could not transfer his overwhelming oval pace to other circuit types, while the reigning champion Power was not able to win a single race and came seventh, a far cry from his 2022 form.